Under Armour Men UA Alter Ego Compression T-Shirt Compression: This ultra-tight, second-skin fit delivers a locked-in feel that keeps your muscles fresh & your recovery time fast. HeatGear fabric, with all the benfits of UA Compression, comfortable enough to be worn all day 4-Way Stretch fabrication allows greater mobility and maintains shape UPF 30+ protects your skin from the sun's harmful rays Anti-Odor technology prevents the growth of odor causing microbes