It is a sock that is specifically designed to conform to the shape of the foot and around the Achilles heel, and its made with our tri-laminate material, so its super comfy. Use for water sports under a neoprene boot or on its own. The top has a neoprene seal that wont allow water inside the sock. They are warm, and stylish and with functional tread underneath to give you additional tread on slick surfaces. Youll know why our Enth Degree F3 Socks are one of our most popular items when you put them and realise how comfortable they are. We knew it we got the design right, when the staff started asking if they could wear them around the office.