The Low Top Ergo Neoprene Socks are designed for comfort. The ergonomic left and right foot specific design reduces bagginess for a warm and smooth fit. The sock helps prevent blisters while wearing open heel fins and protects your feet from hot surfaces in the sun. Ergonomic left and right foot shape Durable elastic bound cuff This sock DOES have Silicone Grip on the bottom 3mm neoprene