C4 Carbon - 0.5 mm Open Heel Socks

C4 Carbon - 0.5 mm Open Heel Socks

The C4 Carbon 0.5 mm Open Heel Socks are designed to improve comfort inside freediving foot pockets without significantly changing the fit of your fins.

Made from ultra-thin 0.5 mm neoprene, they provide a protective layer between your foot and the foot pocket, helping reduce friction, pressure points and the risk of blisters during training and open water diving.

Ideal for freedivers who experience rubbing, pressure points or blisters inside their fin foot pockets.

Size guide

To achieve the best comfort and fit, choose the size corresponding to your usual European shoe size:

If you are between two sizes or are unsure about compatibility with your foot pockets, feel free to contact us before ordering.

These socks are designed to improve comfort and reduce friction. They are not intended to significantly increase foot pocket size.

Minimal thickness, noticeable comfort

Many freedivers experience discomfort not because their fins fit incorrectly, but because prolonged contact between the foot and foot pocket creates rubbing or pressure on specific areas.

The 0.5 mm Open Heel Socks are designed to solve this problem while maintaining the direct feel and responsiveness of your fins. Their minimal thickness allows most divers to use them without significantly altering the fit of an already well-fitting foot pocket.

Designed for freediving

Unlike thicker neoprene socks, the 0.5 mm Open Heel Socks focus on comfort and protection rather than insulation. They provide a smooth interface between the foot and the foot pocket while maintaining excellent sensitivity and control.

The open heel design reduces bulk around the ankle and makes the socks easy to wear with a wide range of freediving bi-fins and monofins.

Ideal for training and regular use

Whether you train in the pool, dive from shore or spend long days in open water, small areas of friction can quickly become uncomfortable. A thin neoprene sock is one of the simplest ways to improve overall comfort during longer sessions.

For many freedivers, socks become a permanent part of their equipment once they experience the difference during extended training sessions.

Main benefits

• Ultra-thin 0.5 mm neoprene: minimal impact on fin fit
• Reduced friction: helps prevent rubbing and blisters
• Improved comfort: especially during longer sessions
• Open heel design: lightweight and low bulk
• Suitable for bi-fins and monofins: versatile compatibility
• Easy to use: simple solution for foot pocket discomfort
• Ideal for training: pool, depth training and open water use

Technical details

Why use socks with freediving fins?

Even a well-fitting foot pocket can create pressure points or friction during longer training sessions. A thin 0.5 mm neoprene sock adds a protective layer between the foot and the foot pocket without significantly changing the fit.

• Freediving Bi-Fins : helps reduce rubbing, improve comfort and create a more secure feeling inside the foot pocket.
• Freediving Monofins : helps prevent pressure points and creates a more comfortable connection between the foot and the monofin foot pocket.

Who should use the 0.5 mm Open Heel Socks?

These socks are ideal for freedivers who already have reasonably well-fitting foot pockets but want additional comfort and protection. They are particularly useful for divers who experience friction, hot spots or blisters during longer sessions.

Because of their minimal thickness, they are also a good choice for divers who do not want to significantly change the fit of their fins.

Kaluna Freediving Opinion

Many freedivers ignore socks until they start experiencing discomfort in their foot pockets. Once rubbing, pressure points or blisters appear, a good pair of thin neoprene socks can make a surprisingly large difference.

The advantage of a 0.5 mm sock is that it improves comfort without significantly changing the fit of your fins. This makes it particularly useful for divers who already have a well-fitting foot pocket but want a little extra protection.

If your fins are noticeably too large, a thicker sock may be a better solution. If your foot pockets already fit well and you simply want more comfort during longer training sessions, the 0.5 mm Open Heel Sock is exactly the type of accessory that can make a difference without adding unnecessary bulk.