Thorlos Thick Cushion Comfort Fit Ski Sock Fire Red, 13 (L) Thick cushioning in ball and heel for warmth, shear protection and comfort Exclusive THOR-LON and THOR-WICK blend for maximum wicking because a dry foot is a warm foot Cushioned arch for better fit (Spandex for support) Cushioned shin and instep protects against shin bite 59% Exclusive THOR-LON Acrylic, 39% THOR-WICK, 2% Spandex