Engineered for Performance, our High Performance socks hug your feet, prevent blisters and keep feet dry and comfortable all day long. Our Cushion socks are designed with high-density cushioning that provides extra protection in high impact zones. Cushion socks are great for those who prefer cushioned comfort without a lot of bulk. Sizing Instructions - Our socks are unisex and fit according to shoe size. If you size up your running shoes, we recommend that you go by your casual shoe size. (See images for size chart). Although the Lycra in our products contracts when it is exposed to water and heat in the wash, it has incredible recovery properties so Feetures socks will stretch back to their original size after the wash. Washing Instructions - Machine wash cold. Hang to dry. No bleach or fabric softeners. For best results, wash socks inside out.