41% merino wool/36% nylon/21% polypropylene/1% COOLMAX polyester/1% Lycra elastane - Twin knit combines a durable exterior with a moisture-wicking interior utilizing zoned performance to keep your feet warm and dry - Form-fitting True Rib leg will stay put without compression - Moisture-wicking odor resistant and temperature-regulating wool blend - Heel arch and toe cushioning - Arch support - Enhanced heel pocket for secure fit - Ribbed channels improve ventilation on leg - Abrasion-resistant yarns in heel arch and toe - Stretch top stays put and reduces tension - Steel toe protection