Wrightsock Men's Fuel Lo Single Pair Socks, Light Grey/Navy, Sock Size:10-13/Shoe Size: 6-12 Inner: 70% Polyester/26% Nylon/4% Lycra; Outer: 68% Polyester/24% Nylon/8% Lycra Machine Wash Two layers trap air for effective insulation from heat and cold Improved moisture management Interaction between layers absorbs friction and prevents blisters Maximum comfort Guaranteed blister free