Carhartt Triple Blend Thermal Crew Socks 43% Acrylic, 21% Polyester, 19% Wool, 16% Nylon, 1% Lycra Spandex Made in the USA and Imported Pull On closure Machine Wash Triple blend thermal sock built for the extreme cold Fast dry technology wicks away sweat so socks stay dry Antimicrobial technology fights the toughest odors Mesh ventilation channels cool feet for breathability Cushioned for comfort and protection