HeatGear Armour, the original high-performance baselayer from Under Armour, is the first thing you put on and the last thing you take off. That's why the performance label made it extra comfortable. The HeatGear material wicks away sweat, dries very quickly, and stretches so you can move freely. It provides excellent coverage while still being lightweight and breathable. Mesh panels under the arms and at the back provide strategic ventilation. Ergonomic design with seams outside high-wear areas increases durability. Raglan sleeves also improve freedom of movement.