FoxRiver Women's Strive Socks 38% nylon, 30% Merino wool, 30% acrylic, 2% spandex Made in US Urfit System provides arch support and memory-knit construction Vented panels remove moisture and keep you dry Reinforced toe and heel add comfort and longer sock life Specially cushioned toe and heel absorb shocks and impacts Lightweight URFit System provides arch support and memory-knit construction