Engineered for Performance, Feetures Therapeutic socks are specifically designed for active people who have special footcare needs. There are no irritating seams. The sock gently hugs the foot to provide added support. Plus, the sock features a comfortable nonbinding top. 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.