Men's Function X Over-the-Calf Midweight Ski and Snowboard SocksOne of Darn Tough's most tech savy snow socks, the new Function X was re engineered to provide max comfort and warmth for resort skiers and riders. Made from midweight merino wool, these ultra smooth socks make all the difference if you decide to head back out after lunch. Terry cushioning in the shin and the 'X' on top of the foot provides warmth while added heel durability protects you run after run. Material Merino Wool: The ultimate fiber for