Fox River Norsk Heavyweight Rag Wool Socks, Warm/Rugged for Cold Winter Days, M 80% wool, 19% nylon, 1% spandex Warm and rugged Classic ragg wool adds thermostatic insulation for cold weather excursions Memory-knit construction keeps shape, wash after wash Reinforced toe and heel add durability and longer sock life Spandex adds stretch and flex for the perfect fit