Heat Tech 2016 Zone3 Neoprene Socks Increased Sock Length: Gives the option to tuck into wetsuit. Velcro Fastener: Helps to reduce water ingress and keeps sock in position. Insulated Neoprene: With titanium lining to help keep feet warm. External Seams with Liquid Seal Finish: Watertight, comfortable and durable. Sole Pattern Grip: Provides protection and grip when walking to the water.