HeatGear fabric, with all the benefits of UA. Compression, comfortable enough to be worn all day. Stretch-mesh underarm panels deliver strategic ventilation. UPF 30+ protects your skin from the sun's harmful rays. Four-way stretch construction moves better in every direction. Material wicks sweat and dries really fast. Anti-odour technology prevents the growth of odour-causing microbes. Mesh panel on back neck with ARMOUR word mark. 84% Polyester, 16% Elastane.