C-Skins Freedom Swim 4mm Swim Socks 3mm Open water swimming socks provide additional warmth without creating too much buoyancy so as to alter your body position. Designed for year round use, these socks will extend your sea time. Featuring a handy split-toe which enables you to wear flip flops to the waters edge. Features: 100% Thermotech Xtend Neoprene - Flexible, lightweight, super hydrophobic external lining that has excellent multi-directional stretch combined with a flexible quick dry thermal lining. Dura Flex Sole - Anatomically structured fit with great durability, protection and comfort. Strata Neoprene - Embossing channels in the neoprene on the top of the foot improve the flow of water. Future Fit 3D - A new construction technology that enables the form of the sock to hug the contours of your foot for ultra sensitive feel and increased warmth. Glued & Blindstitched Seams  - A watertight method of construction that results in superior warmth and maximum comfort. Performance Driven Minimal Panel Design - Strategically positioned seams reduce drag and improve comfort. True Thickness - A warmer thicker product that doesn’t mislead our customers.