FootSmart Men's Microfiber Nylon / Cotton Rib Firm Support Over-the-Calf Socks 10% spandex Firm support gently massages and enhances upward circulation in the legs. Modern knitting technology allows for a layer of cotton next to the skin for a softer, cooler feel. Graduated Support Level: Firm 20-25 mm / Hg. 82% microfiber nylon, 10% spandex, 8% cotton. Note: Light to moderate support products are recommended for first-time wearers. Made in USA. Care: Machine wash on gentle cycle. Lay flat to dry.