Patagonia Ultra Heavyweight Mountaineering Socks

The Ultra Heavyweight Mountaineering Socks by Patagonia is their warmest, mid-calf length sock for mountaineering, trekking, skiing or boarding, and backpacking. Extremely warm and durable, these socks stymie the raw temps of skiing, ice climbing and cold-weather mountaineering. Tightly knit from a blend of 75% merino wool (chlorine-free) for warmth, they also have 12% nylon, 10% polyester and 3% spandex to balance durability and wicking performance. Soft, felted merino wool yarns throughout cushion, insulate, and last the lifetime of the sock. Height is 10.5", allowing for use under big boots.