Neoprene Zero C4 Socks for Freediving and Spearfishing

The Neoprene Zero socks by C4 are designed with careful attention to the specific anatomy of the right and left foot, ensuring a precise and comfortable fit. The construction uses three selected technical materials to provide an optimal balance of stretch, thermal protection, and mechanical resistance.

Materials and Construction

• Instep: stretch fabric that promotes comfort and freedom of movement during finning
• Toes: warm, cut-resistant material to effectively protect the extremities from cold and abrasion
• Sole and heel: non-slip reinforcements provide stable grip and increased durability in underwater environments

Technical Specifications

• Available thicknesses: 1.5 mm and 3.0 mm, suitable for different temperatures and diving conditions
• Available Sizes: XS, S, S/M, M, L, XL, XXL, for a precise, customized fit

Functional Features

The differentiated construction and materials used ensure a sock that is durable yet comfortable, essential for keeping the foot warm during freediving and spearfishing. The non-slip inserts improve stability and safety when walking and in the water.

Neoprene Zero C4 Socks for Freediving and Spearfishing

The Neoprene Zero socks by C4 are designed with precise attention to the anatomical differences between the right and left foot, ensuring an ergonomic and comfortable fit during dives and spearfishing activities.

Materials and Construction

Made with three specific materials, these socks combine targeted technical features for each area of the foot:

• Instep area in elastic material to ensure comfort and freedom of movement
• Tip made from warm, cut-resistant material to effectively protect the toes
• Sole and heel with non-slip reinforcements that improve grip and mechanical resistance on slippery surfaces

Technical Specifications

• Neoprene thickness: 5.0 mm, balanced to maintain warmth and flexibility
• Available size: XL

These socks are ideal for freediving and spearfishing, offering high protection and functionality in the water.

3 mm Double-lined Neoprene Winter Beanie

The winter beanie is made from 3 mm double-lined Neoprene, a material that provides proper thermal protection during freediving and spearfishing in cold waters.

The double lining increases thermal insulation while maintaining excellent stretch and comfort. The elastic structure allows an ergonomic fit to the shape of the head, ensuring a comfortable fit without restricting movement.

Thanks to the fabric’s light weight and flexibility, the beanie provides an effective barrier against heat loss, improving comfort in the water and helping extend freediving session times.

C4 Nylon Buckle Belt for Freediving and Spearfishing

The Nylon Buckle Belt by C4 is designed specifically to meet the needs of freedivers and spearfishers, ensuring strength and durability in the marine environment. The buckle is made from high-strength reinforced nylon, designed to provide secure, reliable fastening during dives.

Materials and Durability

The belt is made from premium-quality silicone, offering significant elasticity with a maximum elongation of 770%. This material stands out for its resistance to saltwater contact, UV rays, and extreme temperature variations, withstanding temperatures from -70°C to +200°C—essential characteristics for underwater use.

Dimensions and Color Options

• Length: 140 cm
• Height: 50 mm
• Thickness: 3.0 mm
• Available colors: Black, White, Brown, Silver

Technical Advantages

• High silicone elasticity for a comfortable, long-lasting fit
• Superior silicone performance compared to traditional rubber, providing greater resistance to weathering and saltwater
• Reinforced nylon buckle resistant to stress during dives and spearfishing activities
• Low maintenance and excellent long-term durability, even with prolonged exposure to the marine environment

C4 Nylon Buckle Belt for Freediving and Spearfishing

The Nylon Buckle Belt by C4 is designed specifically for the needs of freediving and spearfishing, combining high-performance materials with outstanding durability.

The buckle is made from reinforced nylon, a material that ensures high mechanical strength and reliability in the water. The belt, made of silicone, stands out for its remarkable elasticity, with a maximum elongation capacity of 770%, ensuring comfort and adaptability during underwater activity.

Materials and Durability

The silicone used clearly outperforms traditional rubber used for freediving belts, offering superior resistance to saltwater, UV rays, and temperature changes. This material maintains its functional properties across a wide temperature range, from -70°C to +200°C, ensuring performance and durability even in demanding saltwater conditions.

Technical Features

• Belt material: high-elasticity silicone
• Buckle material: durable reinforced nylon
• Maximum silicone elongation: 770%
• Temperature resistance: from -70°C to +200°C
• High resistance to salt and UV rays

This belt is ideal for freediving and spearfishing, offering a reliable, durable, and comfortable solution in the water.

C4 Nylon Buckle Belt for Freediving and Spearfishing

The Nylon Buckle Belt by C4 is specifically designed to meet the needs of freediving and spearfishing, ensuring strength, elasticity, and long-lasting durability.

The buckle is made from high-strength reinforced nylon, providing solid performance and reliability during dives. The belt is made of silicone, a material superior to traditional rubber for freediving belts thanks to its excellent elasticity and resistance to external agents.

Technical features of silicone

• Resistance to extreme temperatures, from -70°C to +200°C
• High resistance to corrosion caused by salt water
• Excellent UV protection, preventing material degradation
• Maximum supported elongation of 770%, ensuring elasticity and adaptability

Dimensional specifications

• Length: 140 cm
• Height: 50 mm
• Thickness: 3.0 mm
• Available in 4 colors: Black, White, Brown, Silver

This silicone belt with nylon buckle is designed to offer comfort and practicality during spearfishing, maintaining stable, long-lasting trim even in saltwater marine environments and during extended dives.

C4 Marseille Belt for Freediving and Spearfishing

The Marseille Belt by C4 is designed specifically for freediving and spearfishing, delivering high-level technical performance and selected materials for the underwater environment.

Materials and Durability

The belt is made from high-quality silicone, a material that far exceeds the performance of the rubber traditionally used in freediving belts. Silicone offers:

• High elasticity for optimal stretch management, up to 570%
• Superior resistance to contact with salt water and UV rays
• High thermal tolerance, from -70°C to +200°C, to ensure integrity even in changing environmental conditions

Dimensions and Variants

• Length: 145 cm
• Height: 50 mm
• Thickness: 5.0 mm
• Available in 5 colors: Black, White, Brown, Silver, Gold

Stainless Steel Marseille Buckle

The quick-release buckle is made from stainless steel, a material chosen for its resistance to corrosion and salt, ensuring reliability and safety during dives.

Benefits for Underwater Use

The use of silicone and the Marseille buckle improves the belt’s functionality in the marine environment through:

• Greater durability and long-term reliability, even with continuous exposure to salt water
• Elasticity that promotes a comfortable fit without constriction and optimal adaptation to the freediver’s movements
• Resistance to weathering and UV rays, ensuring long-term integrity and efficiency

C4 Marseillaise Belt for Freediving and Spearfishing

The Marseillaise Belt by C4 has been specifically designed to meet the needs of freedivers and spearfishers, ensuring strength, elasticity, and long-lasting durability.

Materials and Durability

Made from high-quality silicone, the belt offers superior features compared to traditional rubber belts. Silicone provides excellent resistance to saltwater, UV rays, and temperature fluctuations, with an operating range from -70°C to +200°C. This ensures greater durability even during extended freediving sessions and continuous sun exposure.

Technical Features

• Stainless steel buckles with a quick-release “Marseillaise” mechanism, for simple and reliable fitting and removal
• High silicone elasticity, capable of withstanding elongation up to 570%, ensuring comfort and adaptability to the body
• Length: 145 cm
• Height: 50 mm
• Thickness: 5.0 mm

Variants and Customization

Available in 5 different colors: Black, White, Brown, Silver, and Gold, to make customization easier according to visibility needs and personal preferences during freediving sessions.

C4 Marseille Belt for Freediving and Spearfishing

The Marseille Belt by C4 is an accessory specifically designed for the needs of freedivers and spearfishers, delivering an optimal combination of strength, elasticity, and durability.

Materials and Technical Features

• Stainless steel buckle with a “Marseille” quick-release mechanism, for easy and safe use underwater.
• Belt made from silicone, a material superior to traditional rubber in resistance to continuous exposure to salt water, UV rays, and temperature variations.
• High elasticity with elongation capability up to 570%, ensuring adaptability and comfort while diving.
• Silicone operating resistance tested from -70°C to +200°C, ensuring durability even under varying temperature conditions.

Dimensions and Color Options

• Length: 145 cm
• Height: 50 mm
• Thickness: 5.0 mm
• Available in 5 color options: black, white, brown, silver, and gold, to suit different aesthetic preferences while maintaining functionality and resistance.

Benefits for Freediving and Spearfishing

The choice of silicone over traditional rubber significantly improves the mechanical resistance and longevity of the belt in saltwater environments and under sun exposure, while its high elasticity supports a better fit and comfort while diving. The stainless steel buckle ensures a secure hold and a fast, safe release, essential for freediving and spearfishing.

C4 Marseille Belt for Freediving and Spearfishing

The Marseille Belt by C4 is designed specifically for freediving and spearfishing, delivering high resistance, elasticity, and practicality in the water.

Made from highly durable silicone, this belt stands out for its superior resistance compared to traditional rubber materials, especially against the corrosive action of seawater and exposure to UV rays. Silicone also helps maintain optimal performance across a wide temperature range, from -70°C to +200°C.

Technical features

• Material: Silicone resistant to saltwater, UV rays, and temperature variations
• Buckle: Stainless steel with a Marseille-style quick-release mechanism for ease of use and safety
• Elasticity: Stretch capacity up to 570%, ensuring a snug and comfortable fit
• Dimensions: Length 145 cm, height 50 mm, thickness 5.0 mm
• Available colors: Black, White, Brown, Silver, Gold

The combination of materials and design makes this belt ideal for freediving and spearfishing, ensuring reliability, durability, and thermal comfort even during extended dives.

C4 Marseille Belt for Freediving and Spearfishing

The Marseille Belt by C4 has been specifically designed for the needs of freediving and spearfishing, ensuring strength, elasticity, and durability. Made from high-quality silicone, it stands out for its superior durability compared to traditional rubber belts.

The “Marseille”-style quick-release buckle is made from stainless steel, ensuring a secure and reliable fit during dives.

Technical Features

• Belt material: high-elasticity silicone with temperature resistance from -70°C to +200°C
• Elongation resistance: up to 570%
• Buckle: stainless steel Marseille-style quick-release buckle
• Dimensions: length 145 cm, height 50 mm, thickness 5.0 mm
• Superior resistance to the effects of seawater and UV rays compared to traditional rubber
• Available in 5 colors: Black, White, Brown, Silver, and Gold

The silicone used provides high elasticity and mechanical resistance, preserving its properties in saltwater environments and under intense UV exposure. This results in a reliable belt that maintains its integrity and functionality over time, even after numerous dives.

The belt structure and Marseille buckle allow for a precise fit, ensuring optimal weight distribution during freediving and spearfishing, contributing to comfort and freedom of movement in the water.

C4 Marseille Belt for Freediving and Spearfishing

The C4 Marseille belt is designed specifically for the needs of freedivers and spearfishers, with particular attention to materials and durability in the marine environment.

Materials and Technical Features

The belt is made from extruded silicone, a material that provides high elasticity and superior resistance compared to traditional rubber belts. Silicone maintains its mechanical properties across a wide temperature range, from -70°C to +200°C, and is less prone to deterioration caused by UV rays and saltwater.

The quick-release buckle, “Marseille” style, is made from POM thermoplastic material (Nylon), ensuring strength and reliability during use and fast-release operations.

Dimensions

• Length: 145 cm
• Height: 50 mm
• Thickness: 4.0 mm

Strength and Elasticity

The silicone allows the belt to withstand elongation up to 670% without compromising performance, ensuring a secure, stable fit during freediving and spearfishing.

Available Colors

• Black
• White
• Brown
• Silver
• Gold

Benefits for Freediving and Spearfishing

Compared to traditional rubber belts, this belt offers better long-term durability and greater reliability in saltwater. The elasticity of the silicone helps maintain proper buoyancy trim and ensures comfort during dives, while the Marseille buckle makes fastening and release operations practical and safe.

C4 Marseille Belt for Freediving and Spearfishing

The C4 Marseille belt is designed specifically for the needs of freedivers and spearfishers, ensuring durability and functionality in the marine environment.

Materials and Durability

The belt is made from extruded silicone, a material chosen for its superior resistance to the degrading agents typical of underwater environments, such as salt and UV rays. Silicone maintains its integrity and flexibility at temperatures from -70°C to +200°C, offering longer service life than traditional rubber belts.

The Marseille-style quick-release buckle is made from Nylon and thermoplastic POM, materials known for their high mechanical strength and reliability during freediving and spearfishing use.

Technical Features

• Length: 145 cm
• Height: 50 mm
• Thickness: 4.0 mm
• Maximum supported elongation: up to 670%
• Belt material: high-elasticity silicone
• Buckle material: Nylon and thermoplastic POM

Design and Comfort

The choice of silicone gives the belt remarkable elasticity, resulting in optimal comfort during dives and underwater movement. The Marseille buckle allows fast, secure fastening, making adjustment easy even with gloves or in low-visibility conditions.

Color Availability

The belt is available in 5 color options: Black, White, Brown, Silver, and Gold, allowing customization to match the user’s preferences and compatibility with freediving or spearfishing gear.

C4 Marseillaise Belt for Freediving and Spearfishing

The C4 Marseillaise belt is designed specifically for the needs of freedivers and spearfishers, ensuring durability and functionality in the marine environment.

Materials and Durability

The belt is made from extruded silicone, a material chosen for its superior resistance to the deteriorating agents typical of the underwater environment, such as salt and UV rays. Silicone maintains its integrity and flexibility at temperatures from -70°C up to +200°C, providing a longer service life compared to traditional rubber belts.

The Marseillaise-style quick-release buckle is made from Nylon and thermoplastic POM, materials known for their high mechanical strength and reliability during underwater use.

Technical Features

• Length: 145 cm
• Height: 50 mm
• Thickness: 4.0 mm
• Maximum supported stretch: up to 670%
• Belt material: high-elasticity silicone
• Buckle material: Nylon and thermoplastic POM

Design and Comfort

The use of silicone gives the belt remarkable elasticity, resulting in optimal comfort during descents and underwater movement. The Marseillaise buckle provides fast, secure fastening, making adjustment easy even when wearing gloves or in low-visibility conditions.

Available Colors

The belt is available in 5 color options: Black, White, Brown, Silver, and Gold, allowing customization to suit the user’s preferences and compatibility with freediving and spearfishing gear.

C4 Marseille Belt for Freediving and Spearfishing

The C4 Marseille belt is specifically designed for freediving and spearfishing, with materials and features engineered to withstand the demands of breath-hold diving.

Materials and Durability

The belt is made from extruded silicone, which provides superior resistance compared to traditional rubber commonly used in freediving belts. Silicone offers high elasticity and remains stable across a wide temperature range (from -70°C to +200°C), effectively resisting saltwater exposure and UV rays.

This material ensures longer service life and better performance in marine environments, maintaining elasticity and strength over time.

Quick-Release Buckle

The “Marseille-style” buckle is made from POM thermoplastic material (Nylon), selected for its mechanical strength and light weight, providing a practical and secure quick release during the dive.

Dimensions and Variants

• Length: 145 cm
• Height: 50 mm
• Thickness: 4.0 mm
• Maximum elongation: 670%
• Available colors: Black, White, Brown, Silver, Gold

Technical Applications

The C4 Marseille belt stands out for its combination of elasticity and resistance to marine elements, ensuring a stable and comfortable fit around the body during freediving or spearfishing sessions. Easy adjustment and the buckle’s quick release enhance practicality in the water.

C4 Marseillaise Belt for Freediving and Spearfishing

The C4 Marseillaise belt is designed specifically for freediving and spearfishing, ensuring durability and reliability in the marine environment.

Materials and Strength

The belt is made from extruded silicone, a material that outperforms traditional rubber in elasticity and mechanical strength. Silicone maintains high resistance to extreme temperatures, ranging from -70°C to +200°C, and is effectively protected against the corrosive effects of salt water and UV rays.

The “Marseillaise” style buckle is made from POM thermoplastic and Nylon, providing a reliable, durable quick-release system.

Technical Features

• Length: 145 cm
• Height: 50 mm
• Thickness: 4.0 mm
• Maximum elongation: 670%
• Available colors: Black, White, Brown, Silver, Gold

In-Water Benefits

Silicone provides high elasticity, improving comfort when wearing the belt during freediving sessions or spearfishing trips. In addition, its superior resistance to saline conditions and prolonged sunlight exposure ensures long service life without deterioration.

The quick-release buckle provides practicality and safety during underwater maneuvers, making it easier to adjust and fit the belt to the freediver’s body.

C4 Crotch Belt by Marco Bardi

The crotch belt developed by C4 in collaboration with Marco Bardi is designed specifically for spearfishing and freediving. This anchoring system allows belts and back-mounted ballast systems to be securely fixed, ensuring they do not shift up toward the armpits during duck dives and the descent phase.

With a thickness of 3 mm, the belt provides strength and lightness, offering an ideal balance between mechanical resistance and in-water comfort. The easy attachment allows quick installation and reliable hold, keeping trim stable during the dive.

This accessory is essential for achieving proper trim and improving practicality in the water, preventing annoying upward movement of straps and back-mounted ballast systems during spearfishing.

D&D Collar - Deep & Dynamic for Freediving and Spearfishing

The D&D Collar, Deep & Dynamic, represents the evolution of the Dyno collar made by the C4 brand, designed specifically for freedivers practicing both depth and dynamic disciplines. Its key feature is weight modulation, allowing the ballast to be adjusted from 1 kg up to 4 kg in a single product, ensuring flexibility and precision when fine-tuning underwater trim.

Technical Features

• Made of lead coated with thermoplastic rubber, ensuring mechanical strength and protection against wear
• Highly hydrodynamic design to reduce drag in the water and promote a smooth swimming motion without overloading the neck
• Semi-mobile segments that follow the movements of the thoracic vertebrae, ensuring maximum freedom of movement without restrictions
• Weight distribution concentrated near the balance point of buoyancy forces, improving stability and balance during the dive
• Equipped with safety clips to prevent accidental loss of the segments

Functionality and Modularity

The system consists of a modular collar to which up to 5 semi-mobile rear segments with variable weights can be added, making it easy to move from a 1 kg setup up to 4 kg. The numbered plastic segments allow quick assembly and replacement, making it easier to adapt to different diving conditions.

Available Configurations

• 1.6 kg collar, suitable for depth freediving
• 3 kg collar with 4 rear segments
• 4 kg collar with 5 rear segments, ideal for dynamic freediving when more ballast is required

Additional Details

• Color: black
• Base weight: 1.6 kg
• Rear segments can be added or replaced by purchasing the 4-piece kit or individual 280 gram Dyno and 1 kg Dyno segments

The D&D collar is an ideal technical solution for freedivers and spearfishers who need a modular, comfortable ballast system to optimize trim in both static and dynamic dives, improving weight transfer and freedom of movement during finning.

D&D - Deep & Dynamic Neck Weight for Freediving and Spearfishing

The D&D neck weight is a modular ballast system developed by the C4 brand, designed specifically for the needs of freediving and spearfishing, both for deep dives and dynamic apnea. The name Deep & Dynamic reflects the product’s versatility, allowing the weight to be adjusted from 1 kg up to 4 kg to suit different types of dives.

Technical Features and Materials

The structure is made of lead coated with thermoplastic rubber, a combination that ensures high mechanical strength and durability while maintaining excellent hydrodynamics. The shape of the neck weight is designed to prevent overload on the neck, improving streamlining and comfort during finning.

The ballast segments are semi-mobile and positioned close to the balance center of buoyancy forces, allowing a more natural, less fatiguing trim for the swimmer. Their ability to follow the movement of the thoracic vertebrae ensures complete joint freedom and no restriction of movement in the water.

Weight Modularity and Customization

The system consists of a modular neck weight supplied with additional rear segments of variable weight, easily removable and mountable to adjust the total ballast. This modularity allows the neck weight to be quickly adapted to different dive requirements without compromising comfort or fit.

It is supplied with numbered plastic segments to make it easier to replace the front weights with lightweight segments, creating different weight configurations. The integrated safety clip prevents accidental loss of the segments during use.

Available Configurations

• 1,6 kg – base version ideal for deep dives
• 3 kg – configuration with 4 rear segments for greater weight in dynamic apnea
• 4 kg – complete neck weight with 5 rear segments for maximum modular ballast

Additional Details

• Base neck weight: 1,6 kg
• Color: white
• Material: lead coated with thermoplastic rubber
• Rear segments available individually or in 4-piece kits
• Can be integrated with 280 gram or 1 kg Dyno segments

D&D - Deep & Dynamic Weight Neck Weight for Freediving and Spearfishing

The D&D Neck Weight represents the technical evolution of the well-known Dyno neck weight produced by C4, designed specifically for deep and dynamic freediving. Its design allows the weight to be adjusted from 1 kg to 4 kg by adding or removing segments, providing the versatility needed for different types of dives.

Made of Lead Weight coated with a layer of thermoplastic rubber, the neck weight features a highly hydrodynamic shape that reduces load on the neck, allowing for a smoother, less tiring fin kick. Positioning the weight close to the hydrostatic balance point optimizes in-water trim, improving vertical stability and reducing mechanical resistance during movement.

The system consists of a modular neck weight with semi-mobile rear segments that follow the anatomy and movements of the thoracic spine, ensuring complete freedom of movement and minimizing any joint restriction during freediving sessions.

Technical Features

• Material: Lead Weight coated in thermoplastic rubber
• Hydrodynamic design for greater fluidity in the water
• Modular system with numbered plastic segments for fine-tuning the weight
• Semi-mobile rear segments to adapt to the movements of the thoracic vertebrae
• Safety clip to prevent accidental loss of the neck weight
• Adjustable weight from 1 kg (minimum configuration) up to 4 kg (maximum configuration)
• Base product dimensions and weight: 3.0 kg, white color

Available Configurations

• 1.6 kg neck weight – ideal for deep dives
• 3 kg neck weight – structure with 4 rear segments
• 4 kg neck weight – structure with 5 rear segments

The D&D - Deep & Dynamic Neck Weight is designed to meet the specific needs of spearfishing and freediving in both static and dynamic setups, optimizing the diver’s body balance and ensuring comfort and practicality even during extended dives.

D&D - Deep & Dynamic Neck Weight for Freediving and Spearfishing

The D&D neck weight represents the evolution of the Dyno neck weight from C4, specifically designed for deep freediving and dynamic apnea. The name Deep & Dynamic highlights its versatility: it allows the weight to be adjusted from 1 kg up to 4 kg in a single modular system optimized for spearfishing and deep freediving.

Technical Features

• Adjustable weight from 1 kg to 4 kg with removable, adjustable segments
• Material: lead coated in durable, hydrodynamic thermoplastic rubber
• Shape designed to minimize load on the neck and improve finning
• Semi-mobile rear segments follow the movement of the thoracic vertebrae, ensuring full joint freedom
• Equipped with a safety clip to prevent accidental loss during dives
• Color: black

Functionality and Benefits

The weight distribution is optimized to work close to the body’s center of gravity, balancing buoyancy forces and improving freediving efficiency. Thanks to the semi-mobile segments, the neck weight does not restrict the swimmer’s movements, maintaining fluidity and comfort during descent and ascent.

Available Configurations

• 1.6 kg: base configuration ideal for deep dives that require a light, balanced trim
• 3 kg: neck weight with four rear segments for medium buoyancy compensation in dynamic apnea
• 4 kg: neck weight with five rear segments for more demanding dynamic apnea sessions, with a higher ballast load

Included Equipment

• Numbered plastic segments to make assembly and weight adjustment easier
• Safety clip for fastening and prevention of accidental loss

The D&D neck weight provides a modular, functional system for quickly adjusting ballast balance in freediving, combining hydrodynamics, comfort, and freedom of movement, key aspects for spearfishing and freediving.

D&D Neck Weight - Deep & Dynamic for Freediving and Spearfishing

The D&D Neck Weight represents the evolution of the C4 Dyno neck weight, designed specifically for freediving in both depth and dynamic disciplines. The name Deep & Dynamic reflects the product’s technical versatility, allowing the weight to be adjusted from 1 kg up to 4 kg in a single system adaptable to different diving needs.

Technical Features

• Made from lead coated with a layer of thermoplastic rubber to ensure mechanical strength and long-lasting durability.
• Highly hydrodynamic shape designed to reduce drag and minimize load on the neck, improving the fluidity of the fin kick and freedom of movement while freediving.
• Semi-mobile segments that follow the anatomy of the thoracic vertebrae, allowing a more natural, unrestricted trim while swimming.
• Modular system consisting of a main neck weight to which segments can be added or removed at the rear to vary weight and trim.
• Equipped with numbered plastic segments to make assembly easier and allow precise load adjustment.
• Integrated safety clips to prevent accidental loss of the segments during the dive.

Weight Configurations

The D&D Neck Weight is available in three configurations designed for different types of diving:

• 1.6 kg - ideal for deep dives, providing efficient balance while reducing bulk.
• 3 kg - neck weight equipped with 4 rear segments for an intermediate trim adaptable to more agile dynamics.
• 4 kg - full configuration with 5 rear segments for dynamic dives that require greater ballast load.

Benefits for Freedivers and Spearfishers

Thanks to its adjustable weight and distinctive ergonomic shape, the D&D Neck Weight significantly improves trim control during freediving and spearfishing. The weight load is optimized close to the center of buoyancy, ensuring better balance and greater movement efficiency.

The system’s adaptability with semi-mobile segments and the lightweight coating material contribute to excellent comfort during extended use and complete joint freedom.

D&D Modular Weight Neck Collar - Deep & Dynamic for freediving and spearfishing

The D&D Neck Collar by C4 represents an important evolution of the traditional Dyno neck collar, designed specifically for those practicing deep freediving and dynamic apnea. Its main feature is its adjustable weight, which can range from 1 kg up to 4 kg depending on the needs of the dive, providing a single product adaptable to different buoyancy setups.

Technical features and materials

Made from lead coated with thermoplastic rubber, the neck collar features a hydrodynamic shape designed to optimize finning fluidity and reduce load on the neck, improving comfort and freedom of movement during freediving.

The weight is positioned close to the body’s center of gravity, aligning with buoyancy forces to make balancing in the water easier. In addition, the semi-mobile rear segments are designed to follow the natural movement of the thoracic vertebrae without limiting the swimmer’s mobility.

Modularity and configurations

The system consists of a modular base neck collar to which removable, numbered rear segments made of plastic attach, allowing the weight to be adjusted quickly and safely, also thanks to safety clips that prevent accidental loss.

The available configurations are:

• 1.6 kg Neck Collar - ideal for deep dives, with reduced weight for greater agility
• 3 kg Neck Collar - version with 4 rear segments for a balanced and versatile buoyancy setup
• 4 kg Neck Collar - with 5 rear segments for dynamic apnea and increased ballast

Benefits during underwater use

• Precise weight adjustment to easily adapt to the type of freedive
• Reduced cervical stress thanks to the ergonomic shape and soft coating
• Maximum freedom of movement ensured by the semi-mobile segments that move with the spine
• Simple and secure assembly with numbered segments and anti-loss clips

The D&D Neck Collar is a targeted technical solution for freedivers and spearfishers who need a customizable weight system that improves efficiency, comfort, and buoyancy control in the water.

C4 Dyno Neck Weight 4.0 kg for Freediving

The Dyno Neck Weight 4.0 kg is a modular weight system designed specifically for spearfishing and freediving by C4. Its highly hydrodynamic design minimizes bulk and distributes weight ergonomically, helping avoid overloading the neck while swimming underwater.

Technical Features

• Hydrodynamic shape engineered to optimize force transmission and reduce water resistance.
• Semi-mobile segments that follow the natural movement of the thoracic vertebrae, ensuring full joint freedom and comfort during dives.
• Modular segments with variable weight, secured with screw pins for quick and easy assembly.
• Option to customize the load by adding 280 g Dyno segments, sold separately.
• Resistant and durable materials to ensure stability and reliability in saltwater.
• Available color: white.

Benefits for Freedivers and Spearfishers

Positioning the weight close to the body’s center of gravity helps effectively balance buoyancy forces, improving stability in the water and the fluidity of the fin kick. Thanks to improved weight distribution and modular adjustability, the Dyno Neck Weight helps maintain a natural posture, reducing fatigue and restrictions in neck and back movement.

Assembly and Customization

1. Remove or add segments according to the desired weight.
2. Secure each segment using the screw pin, ensuring a firm and stable hold.
3. To increase weight, add the supplementary 280 g Dyno segments available separately.
4. Adjust the neck weight so it fits comfortably around the neck without compression.

Dyno Neck Weight 4.0 kg for Freediving – Modular Weight System

The Dyno Neck Weight in 4.0 kg, designed by C4, is a weight system specifically developed for spearfishing and freediving. Its hydrodynamic shape reduces bulk and does not overload the neck during finning, improving efficiency and fluidity of underwater movement.

Design and Comfort

The neck weight is made up of semi-mobile segments that adapt to the movement of the thoracic vertebrae, ensuring full joint freedom with no restriction of movement. This feature increases comfort during the dive while keeping the weight concentrated close to the balance point of buoyancy forces, optimizing trim in the water.

Modularity and Weight Customization

The segments, with varying weights, are easy to assemble and disassemble thanks to axles with locking screws. This allows the load to be precisely customized according to the specific needs of the freediver or spearfisher.

• Additional 280-gram Dyno segments available separately to increase weight
• Easy assembly and adjustment according to the dive profile

Technical Features

• Type: modular neck weight system for freediving
• Standard total weight: 4.0 kg
• Shape: optimized for hydrodynamics and neck comfort
• Materials: mechanically strong and durable
• Color: black

Benefits for Freedivers and Spearfishers

The Dyno Neck Weight improves thrust transmission during freediving thanks to the well-distributed weight near the body’s center of gravity. Its modular structure contributes to a customized trim, enabling smoother and less tiring underwater movement, with optimized neck comfort and minimized inertia.

Naifu S Arm Knife for Freediving and Spearfishing

Naifu S is an arm knife designed with an ergonomic shape to ensure comfort and practicality during freediving and spearfishing activities.

Blade Technical Features

The blade, 66.5 mm long, is made from AISI420B stainless steel, known for its combination of strength and hardness. The blade is extremely sharp and includes an integrated line cutter. Its internal structure extends along the entire length of the handle, ensuring optimal rigidity and greater reliability in the water.

The blade heat treatment involves vacuum hardening at 1020°C, followed by nitrogen cooling at 20 atm, to improve hardness and mechanical strength.

Handle and Sheath

The handle and sheath are made from recyclable POM acetal resin, a plastic material characterized by high rigidity, low moisture absorption, and anti-friction properties, ideal for use in underwater environments.

The knife measures 144 mm in overall length, ideal for ensuring control and safety. The locking system uses a central retaining tooth that makes both fastening and release easier, improving practicality and speed of extraction during the dive.

Fastenings and Accessories

• Equipped with two rubber straps with stainless steel loops for fastening to the arm or leg, ensuring stability during underwater activity.
• The sheath features a rear hole for optional bungee mounting, increasing fastening and safety options.

Technical Specifications

• Blade material: AISI420B stainless steel
• Blade length: 66.5 mm
• Overall length: 144 mm
• Handle and sheath color: Black

Naifu S arm Knife for freediving and spearfishing

The Naifu S is an arm Knife designed with an ergonomic shape specifically developed for the needs of freedivers and spearfishers. The 66.5 mm blade is made from AISI420B stainless steel with vacuum heat treatment at 1020°C and nitrogen cooling at 20 atm, ensuring high hardness and mechanical strength while maintaining a long-lasting edge.

The blade shape includes an integrated line cutter, while its internal tang runs the full length of the handle, ensuring rigidity and effective thrust transfer during underwater use.

Materials and technical features

• Handle and sheath made from POM acetal resin, a rigid, recyclable plastic material with low moisture absorption and anti-friction properties that improve comfort and handling in the water.
• Colors: white handle, black sheath for easy recognition in the water.
• Total length Knife: 144 mm.
• Attachment with central retaining tooth that works both when locking and releasing, making extraction quick and safe during use.

Accessories and attachment

• Equipped with two rubber straps with stainless steel loops for stable attachment to the leg or arm, ensuring comfort and safety during spearfishing.
• Sheath with rear hole for optional anchoring of an additional elastic cord, increasing Knife stability during descent and retrieval.

Specific applications

The Naifu S is ideal for freediving and spearfishing, thanks to its combination of materials resistant to marine corrosion, compact design, and technical solutions engineered to ensure practicality, durability, and safety while diving.

Naifu Knife for Freediving and Spearfishing

The Naifu knife features an ergonomic design engineered to be comfortably secured to the calf or belt, ensuring practicality and quick extraction during freediving and spearfishing.

Blade technical features

The 94 mm blade is made from AISI420B stainless steel, vacuum hardened at 1020°C and nitrogen cooled at 20 atm, a process that ensures high rigidity and mechanical strength. The blade incorporates a line cutter and extends internally along the full length of the handle, increasing stability and precision in use.

Handle and sheath

The handle and sheath are molded from POM acetal resin, a recyclable plastic material known for its high rigidity, low moisture absorption, and low-friction properties, essential for ensuring comfort, durability, and easy extraction in the underwater environment.

The sheath locking system features a central retention tooth that provides secure locking while remaining easy to release, allowing the knife to be quickly drawn even while wearing dive gear.

Dimensions and attachment

• Blade length: 94 mm
• Total knife length: 204 mm
• Handle and sheath color: black

The knife is supplied with two rubber straps equipped with stainless steel loops for secure attachment to the leg or arm. On the back of the sheath there is a hole for the optional addition of an elastic band, increasing anchoring versatility according to the preferences of the freediver or spearfisher.

Ronin C4 – Knife for Spearfishing

Ronin C4 is a knife specifically developed for freediving and spearfishing, featuring an ergonomic and functional design.

Blade Features

The blade, 81 mm long, is made of AISI420B stainless steel, a material known for its corrosion resistance in marine environments. The blade extends through the full length of the handle, ensuring rigidity and stability during use. It is available with a razor grind for a clean cut and a serrated section specifically designed to make cutting lines easier. In addition, the line release notch allows speargun shafts to be freed quickly during spearfishing.

Handle and Sheath

The handle is co-molded with the knife body in POM acetal resin, a recyclable plastic material that offers high rigidity, mechanical strength, and low moisture absorption. Its ergonomic shape ensures a secure, practical grip during dives.

A high-power safety whistle is integrated into the base of the handle, useful for emergency signaling in the water.

The sheath, also made of black POM, features two double mounting holes for belt attachment. Its design includes a partial opening that allows the sheath to be repositioned on the belt without removing the weights, ensuring easy gear management during dives.

Technical Specifications

• Blade material: AISI420B stainless steel with anti-corrosion PVD treatment
• Blade length: 81 mm
• Overall length: 180 mm
• Handle and sheath: black POM acetal resin, co-molded
• Integrated accessories: high-power safety whistle
• Attachment system: sheath with double belt mounting holes, suitable for use while wearing weights

Ronin C4 Spearfishing Knife

Ronin C4 is a knife specifically designed for spearfishing and underwater use, featuring an ergonomic and functional design to ensure comfort and precision in the water.

Technical Blade Features

• Made from AISI420B stainless steel, known for its corrosion resistance in marine environments
• 81 mm blade length
• Razor-sharp grind for a clean, precise cut
• Part of the blade features specific serrations for efficient line cutting
• Equipped with integrated shaft extractors to help remove shafts in recovery situations
• Partial anti-corrosion PVD treatment to increase durability in saltwater
• The blade extends the full length of the handle, ensuring optimal rigidity and mechanical strength

Handle and Sheath

The handle is made by co-molding it with the blade body using POM acetal resin, a recyclable material characterized by high rigidity, low moisture absorption, and low-friction properties, ideal for use in underwater environments.

A high-power whistle is integrated at the base of the handle for emergencies during freediving.

The sheath in POM features two double holes for secure belt attachment and has a partial opening that allows it to be moved without removing the weights, increasing ease of use during spearfishing.

Dimensional Specifications

• Total length: 180 mm
• Handle color: Red
• Sheath color: Black

Benefits for Spearfishing

• Rigidity and mechanical strength of the blade and co-molded body ensure stability during cutting
• Ergonomic POM handle improves comfort and safety while freediving
• Sheath with belt attachment optimized to avoid interfering with the weights, ensuring practicality during underwater operations
• Integrated emergency whistle, a useful safety tool for freediving

Ronin C4 – Belt Knife for Spearfishing

Ronin C4 is a belt knife designed with an ergonomic layout specifically for freediving and spearfishing, providing practicality and durability in the water.

Blade Features

• Made from AISI420B stainless steel for corrosion resistance and durability
• 81 mm blade length with razor grind and serrations for efficient line cutting
• Surface treatment with anti-corrosion PVD coating to increase service life in marine environments
• The blade extends the full length of the handle for high structural rigidity
• Integrated shaft extractors for managing speargun shafts

Handle and Sheath

• Handle co-molded with the knife body, made from recyclable POM acetal resin, known for its high mechanical strength and low water absorption
• Ergonomic, rigid Handle for optimal comfort and control during underwater use
• Equipped with a high-power safety whistle integrated into the base, useful for emergencies in the water
• Sheath made from the same POM material, with dual holes for secure belt attachment
• Sheath design with a partial opening that allows it to be repositioned on the belt without removing the weights

Technical Data

• Blade material: AISI420B stainless steel with PVD coating
• Blade length: 81 mm
• Total knife length: 180 mm
• Handle color: white
• Sheath color: black

Features and Benefits

The co-molded construction of the handle and body ensures high rigidity and mechanical strength, an essential factor for freediving and spearfishing activities. The specially shaped blade with razor grind and serrations makes line cutting efficient, while the shaft extractors make it easier to manage shafts without compromising safety or smooth operation.

The use of POM resin for the Handle and Sheath ensures light weight, moisture resistance, and ergonomics suited to precise control of the knife in the water. In addition, the integrated whistle provides a useful safety feature in underwater emergency situations.

C4 Cap for Shaft Protection

The C4 Cap is specifically designed to protect the tips of Shafts used in freediving and spearfishing. Made from durable materials, it provides effective protection against impacts and the risk of damage during transport or storage.

The cap features holes that allow the shooting line to pass through, making it easier to secure or retrieve without the risk of losing the cap. This feature improves ease of use in the water and during equipment assembly or maintenance.

Thanks to its high visibility, the cap is easy to locate, reducing search time and increasing safety when handling the shaft.