Under Armour UA MK-1 Originators SS T-Shirt. Extra soft, smooth and incredibly light HeatGear fabric® provides maximum comfort.In the armpits and back there are panels made of finely mesh material for strategic ventilation.4-Way Stretch technology allows for greater flexibility of clothing in any direction.The material is a great sweat wicker and it dies very quickly.Anti-odor technology prevents the appearance of an unpleasant odor.Moulded hem for better fitting to your physique.