Hi-Tec Merino Wool Crew Sock merino-wool 63% Merino Wool, 32% Nylon, 5% Spandex Merino Wool aids in moisture management, Mesh Ventilation panels provide breathability, Arch Compression secure sock around the foot to reduce sagging Ribbed Leg conforms around the leg helping to keep sock in place, Welt Top work injunction with rib leg to hold socks up,Cushioned Footbed provides cush comfort in high impact areas Machine wash inside out in warm water, no bleach. Tumble dry low. Do not dry clean USA