The Mountain Sock is our thickest design, and that&';s intentional. Terry loop padding runs across the entire footbed, from toe to heel. At mile twelve, your feet won&';t hurt. At mile twenty, they&';ll still be good. The liner is 39% merino wool, with the remainder synthetic for durability. Merino manages moisture naturally, provides warmth even when damp, and resists odor through multi-day wear. The mid-calf height-nine and a half inches-keeps snow out of your boots and brush off your legs. These socks have bulk. That&';s the design. You need roomy boots to accommodate them, but that&';s exactly where they belong. Your insulated winter hikers. Hunting boots with generous toe boxes. The footwear you wear for serious work in cold conditions.