The Icebreaker Snow Liner Over the Calf is back. Designed to keep active feet comfortable inside a ski, snowboard or mountaineering boot, this ultralight liner sock gives your feet an extra layer of protection in cold weather. Highly breathable performance and a contoured fit, with support zones over the Achilles and instep to keep the sock in place, reinforced heel and toe areas for comfort and durability, and a breathable forefoot zone for improved ventilation. The seamless toe closure reduces bulk and helps prevent blisters when hiking or touring in the backcountry.