US Sizing: Small: Women&';s 5-7.5 Medium: Women&';s 8-10.5, Men&';s 6-8.5 Large: Women&';s 11-13.5, Men&';s 9-13 These Ruffle Quarter Socks are lightweight, sweat-wicking, and include just the right amount of frill. Who says your running &';fits shouldn&';t include a little whimsy? We love it for: everyday running and racing Sweat-wicking Light cushion Quarter-length Fabric: 73% nylon, 18% polyester, 5% elastane, 4% combed cotton