Gore Running Wear Men’s Air 2.0 Shirt 82% POLYESTER, 18% ELASTANE, MESH: 100% POLYESTER Imported Cooling and venting shirt for the summer season. Slim fitting with extra venting performance in high sweat level areas. Slim fit. Contrast flat-lock seams Mesh inserts for ventilation under arms and in back. Reflective print on back Reflective flag.