100% Polyester Imported Durable, Moisture-Wicking Fabric: Constructed of 100% polyester, these thermal shirts for men feature Intellifresh(tm) odor-control on-the-fabric technology powered by Silvadur(tm) Athletic Fit: The perfect long-sleeve workout shirts for men, our men’s thermals feature an extended body and sleeves, a tagless design, and flat seams for a smooth, ultra-comfortable fit Efficient Design: Long-sleeve shirt for men features a crew neckline for easy layering as a mid or outer layer; Drop tail maintains coverage without restricting freedom of motion Comfortable Base Layer: Our men’s thermal underwear top is engineered with a single layer that wicks away moisture to help keep you dry and comfortable Multipurpose Apparel: Our men’s base layer crew neck top allows for minimal layering in cold to very cold weather at a medium to high activity level