SurfGrip Surf Grip Boots Brushed Lining 5mm Round Sox XL (27cm - 27.5cm) In addition to the effects of stretch heat generation and stretch energy, this ultimate winter sock uses sustainable materials that exhibit far-infrared heat storage and insulation, providing warmth, lightness, and amazing quick-drying properties. The rubber material on the inside of the ankle enhances the fit and significantly reduces water ingress. 5mm thick round toe type. 5mm Round Socks *This product is not completely waterproof. Thank you for viewing.