With mesh fabric in high-heat areas, the Nike Vapor Socks are designed to help keep your feet cool during the action. Sweat-wicking technology wicks away sweat to help keep you dry and comfortable, while cushioning in the right spots helps cut down on impact as you run. Sweat-wicking technology helps you stay dry, comfortable and focused. Cushioning helps absorb impact for optimal comfort. Mesh fabric adds ventilation. A dynamic arch band at the midfoot provides a supportive feel and a close fit. The ribbed welt at the top helps keep the sock in place 58% polyester/31% nylon/6% cotton/5% spandex Machine wash.