Compression: Ultra-tight, second skin fit 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 4-way stretch fabrication allows greater mobillity in any direction Moisture Transport System wicks sweat & dries fast Anti-odor technology prevents the growth of odor causing microbes