Under Armour Men's Hike Charged Crew Boot Socks 40% Acrylic, 37% Wool, 11% Polyester, 10% Nylon, 2% Spandex Imported Medium cushion throughout provides comfort and warmth without bulk Embedded arch support helps reduce foot fatigue Arm our dry material wicks moisture, accelerates evaporation Arm our Block technology helps prevent growth of odor-causing bacteria CHARGED wool provides superior moisture management, insulation and comfort