NIKE Men's Racer Running T-Shirt Large Black-Volt 100% polyester FABRIC: 100% polyester Dri-FIT. Reflective elements keep you safe even when light is low. Plenty of lightweight breathability. Mesh and Dri-FIT fabrics. Zero-irritation design Battles back against sweat so you stay light and fresh. Closed hole mesh ensures chafing isn't an issue.