82% Thorlon Acrylic, 9% Nylon, 5% Spandex, 4% X-Static * Exclusive Thorlon construction for resilience, durability and better wicking * Sock size 11 fits Men"s shoe size 5.5-8.5, sock size 13 fits shoe size 9-12.5 and sock size 15 fits shoe size 13-15 * Moderate cushioning in ball/heel for reducing shock, impact, shear and blisters * Flat knit at instep and thin cushioning in the arch improves fit