Description Klim Aggressor Sock 2.0 Teton Merino Wool blended w/ acrylic, Polyamide Nylon, Lycra for durability & comfort (36% Merino Wool, 31% Acrylic, 11% Nylon, 22% Elastane) Made of European sourced yarns Reinforced toe, heel, sole Engineered Terry Loop for strategic cushioning and warmth Arch & ankle support stretch bands Patterned front mid ankle bend for reduced bulk Tubular cuff for better fit & stretch recovery Over-the-calf height SM = 4-6, MD = 7-9, LG = 10-12, XL = 13-15