Wigwam's Eira socks are an ultra-lightweight, merino blend. Elasticized arch and ankle, and seamless tow closure make these long socks a winter favourite. Great for layering! Made in USA. Materials: 48% Merinio Wool, 47% Stretch Nylon, 5% 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.