Thorlos Women's Thick Cushion Running Low Cut Socks Thorlon fibers effectively wick away moisture to keep the foot dry. Thick cushioning in the ball of foot and heel reduces shock and impact, while helping to prevent blisters. Thin cushioning at the arch reduces foot pressure and adds protection from foot shock. 87% Thorlon acrylic, 12% nylon, 1% spandex. Made in USA. Care: Machine wash inside out in lukewarm water. Tumble dry low. Liquid fabric softener recommended.