You can't go wrong with these socks from Dan Post! Featuring an advanced design, this work sock outperforms ordinary work socks. The reinforced heel and toe features Endurall« friction reduction design. Made of 70% ring-spun cotton/13% acrylic/10% SORBTEK« A.M.Y.«/3% FYnesse« Endurall«/2% nylon/2% spandex. Fits men's shoe sizes: 9=S(7-10.5), 10=M(10.5-13), 13=L(13.5 & up). Proudly made in the U.S.A.!