Regular price SFr. 33.00
Unit price per
C4 Carbon - 0.5 mm Open Heel Socks
The C4 Carbon 0.5 mm Open Heel Socks are ultra-thin neoprene socks designed for freediving foot pockets. They add a light protective layer between your foot and the fin without significantly changing the fit.
Use them when your fins already fit well, but you want less rubbing, fewer pressure points and more comfort during pool training, depth sessions or long open-water dives.
The 0.5 mm thickness is the key point: these socks are made for comfort and sensitivity, not for thermal insulation or making oversized foot pockets feel much smaller.
Why use 0.5 mm socks?
Even a well-fitting foot pocket can create friction during longer sessions. Small pressure points around the toes, instep or heel opening can become annoying fast, especially during repeated pool sets or long depth-training days.
A thin 0.5 mm sock gives you just enough protection to improve comfort while keeping the direct feel and responsiveness of your fins.
Main benefits
- Ultra-thin 0.5 mm neoprene with minimal impact on fin fit
- Designed for open-heel freediving fins
- Helps reduce rubbing, hot spots and pressure points
- Smooth outer surface for easy entry into the foot pocket
- Lined inside for comfort against the foot
- Internally taped construction for better long-term bonding durability
- Open heel design with low bulk around the ankle
- Suitable for bifins and monofins when the foot pocket fit is already close
Minimal thickness, noticeable comfort
These socks are not meant to change your fin size. They are meant to make an already good fit more comfortable.
If your foot pockets are too large, choose a thicker sock or reassess the fin size. If your foot pockets fit well but create rubbing or pressure during longer sessions, the C4 0.5 mm Open Heel Socks are the cleaner solution.
Size guide
| Size | EU shoe size |
|---|---|
| S | 35–38 |
| M | 39–42 |
| L | 42–44 |
| XL | 45–47 |
If you are EU 42, both M and L can be relevant depending on foot shape and preferred fit. Choose M for a tighter sock fit and L for a more relaxed fit or wider foot.
Recommended fin pairings
These socks are a practical comfort upgrade for high-performance foot pockets where fit and sensitivity matter.
- C4 Protech Freediving Fins: the most natural C4 pairing if you want a thin sock inside a C4 foot pocket without adding unnecessary bulk.
- Double K Delfit Carbon Bifin: useful when you want a very thin comfort layer while keeping a precise carbon-bifin feel.
- Cetma Taras Monofin: a good option if you want to reduce friction in a close-fitting monofin foot pocket without adding much volume.
- Cetma Taras Bi-Fins: suitable as a minimal protective layer for precise Taras foot pockets.
Technical details
| Brand | C4 Carbon |
|---|---|
| Product | 0.5 mm Open Heel Socks |
| Product type | Freediving neoprene socks |
| Material | Pre-compressed neoprene |
| Thickness | 0.5 mm |
| Outside finish | Smooth |
| Inside finish | Lined |
| Construction | Internally taped |
| Heel design | Open heel |
| Recommended use | Freediving, pool training, open-water diving, bifins and monofins |
| Available sizes | S, M, L, XL |
Kaluna Freediving opinion
This is the sock to choose when your fins already fit correctly but start to rub during longer sessions. The 0.5 mm thickness improves comfort without making the foot pocket feel noticeably smaller.
If your fins are loose, go thicker. If your fins fit well and you just want less friction, this is exactly the right type of sock.
FAQ
Do these socks change the fit of my fins?
Only minimally. The 0.5 mm thickness adds a very thin layer, mainly for comfort and friction reduction. It is not the right solution for foot pockets that are clearly too large.
Are these socks warm?
Not significantly. At 0.5 mm, they are primarily comfort socks, not thermal socks. Choose thicker neoprene socks if warmth is the main goal.
Can I use them with bifins?
Yes. They are designed for open-heel freediving fins and work well with bifins when the foot pocket already fits correctly.
Can I use them with a monofin?
Yes, if the monofin foot pockets are already close-fitting. The socks can help reduce rubbing and pressure points without adding much volume.
Which size should I choose?
Choose your normal EU shoe-size range: S for 35–38, M for 39–42, L for 42–44 and XL for 45–47. If you are EU 42, choose M for a tighter fit or L for more comfort.
Are these socks suitable for oversized foot pockets?
No. They are too thin to compensate for a clearly oversized foot pocket. Use a thicker sock or choose a better fin size.
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