87% Polyester/13% Elastane Imported Machine Wash The Thermo Cool fabric is made of two high-tech polyesters and has a brushed inside offering superb thermoregulation in fair and cold conditions Craft is the official apparel and footwear sponsor of Spartan Race Thin, lightweight and elastic fabric for freedom of movement Elastic silicone grippers keep the knee warmers in place Ergonomically placed seams follow the moving body Elastic seams in contrast color