Heat Gear Armour is our original performance baselayer-the one you put on first and take off last. So we made it extra comfortable by wicking sweat and stretching so you can move no matter what. Super-light Heat Gear fabric delivers superior coverage without weighing you down. Mesh underarm & back panels for strategic ventilation. Material wicks sweat & dries really fast. Anti-odor technology prevents the growth of odor-causing microbes. Ergonomic design keeps seams off high abrasion areas & increases durability.