American Apparel Unisex Tri-Blend Short Sleeve Track Shirt-Athletic Blue 50% polyester Polyester retains shape and elasticity; Cotton lends both comfort and durability; addition of Rayon makes For a unique texture and drapes against the body for a slimming look Durable rib neckband Tri-Blend (50% Polyester / 25% Cotton / 25% Rayon) construction Unisex size - women may prefer to order one size down.