Wigwam's Merino Lite Hiker's unique blend of Merino Wool, polyester/Tencel® and an elasticized arch make it the perfect fit for lengthy adventures. Features include: stay put leg and top, long wearing heel and toe, elasticized arch, foot hugging fit and comfort, and seamless toe closure. Materials: 50% Merino Wool, 34% Stretch Nylon, 13% Polyester, 2% Tencel®, 1% Spandex. . Sizes: S = Womans 4-7, M = Mens 5-9.5 Womans 6-10, L = Mens 9-12 Womans 10-13, XL = Mens 12-15.