Hi-Tec Full Thermal Crew Sock acrylic 74% Acrylic, 14%Wool, 10% Nylon, 2% Spandex Full Thermal construction regulates tempratures within the sock, Premium Wool Blend helps aid in moisture management Ribbed Comfort Cuff conforms around calf helping to keep sock in place, Construted for warth & durability Machine Wash - Warm, Tumble Dry- Low, Non Chlorine Bleach as needed USA