Wigwam's Hiker Essential socks combine the warmth of a sock with the moitsture control of a liner with patented INgenius® technology. A reinforced heel and toe for durability, and elasticized arch and ankle for a great foot-hugging fit. Seamless toe closure eliminates abrasion. U.S. Patent No. 6,612,136 Made in USA. Materials: OUTER: 46% Merino Wool, 36% Stretch Nylon, 14% Polypropylene, 2% Spandex, 2% Stretch Polyester, LINER: 100% Olefin. . Sizes: S = Womans 4-7, M = Mens 5-9.5 Womans 6-10, L = Mens 9-12 Womans 10-13, XL = Mens 12-15.