42% Merino Wool, 34% Acrylic, 20% Polyester, 3% Nylon, 1% Spandex Size:Mens US 10-13,Crew Socks,4 pairs per package Knitting method to ensure no itching, the material in contact with the skin is acrylic. Comfortable and warm in winter and keep out the cold and moisture, no overheat. The casual merino wool socks are elastic to fit. easily match shoes, boots and sneakers. Easy to care for, wash in cold water without bleach, do not iron.