Under Armour HeatGear® Armour men's short-sleeved base layer top. The HeatGear ® Armour T-shirt is the original performance base layer, the baselayer you put on first and take off last. So we've made it more comfortable with its sweat-wicking, stretchy textile so you can move no matter what. Features: Super-lightweight HeatGear® fabric offers superior coverage without weighing you down. Mesh panels under arms and back for strategic ventilation. Material wicks away perspiration and dries very quickly. Ergonomic design protects seams in high abrasion areas and increases durability. Hybrid raglan sleeve construction for greater range of motion and comfort. Label on back of neck for your initials or number. Body: 84% polyester/16% elastane. Mesh: 92% polyester/8% elastane.