blueseventy Thermal Swim Socks - for Triathlon Training and Cold Open Water Swimming INSULATED - 2mm Yamamoto super stretch neoprene with zirconium liner at the foot reduces water absorption and creates an extra insulating layer. LONG LENGTH - Longer length provides additional warmth and reduces water entry. BOTTOM GRIP - Textured bottom helps prevent injury to feet when walking or running on rocky surfaces. They come in handy on long transition runs too. PERFECT FOR - open water swimming and triathlon training LONGER SWIM SEASON - the blueseventy Thermal Sock will allow you to get into the water sooner and swim later into the season.