"Keep feet warm for the long haul with Hollow Alpaca Boot Socks! Hollow's premium blend of soft Peruvian alpaca fibers delivers 3 times more warmth than wool, wicks away moisture, naturally resists odor, and keeps feet comfortable in temperatures ranging from -20F to 50F. 70% alpaca fibers/27% stretch nylon/3% spandex. 14""L from cuffs to heels. Men's Sizes M (6-9), L (9.5-12), XL (12.5-15). Machine wash. 70% alpaca fibers/27% nylon/3% spandex 3 times warmer than wool Moisture-wicking and odor-resistant Soft fibers provide all-day comfort Keeps feet comfortable in temperatures ranging from -20F to 50F"