Gore Running Wear Men's Mythos 4.0 Shirt 100% POLYESTER, MESH: 100% POLYESTER Imported Cooling and venting but most of all, this shirt has a 360 degrees reflex design to secure your visibility from all angles Cooling and venting but most of all, this shirt has a 360 degrees reflex design to secure your visibility from all angles. Slim fit Flat-lock seams Flat-lock seams with reflective print Mesh inserts for better ventilation Reflective print on sleeves