Not your ordinary long underwear, the Under Armour Base 4.0 Long-Sleeve Crew Shirt is built to take on even the most brutal cold without adding excess bulk. Rugged 96% polyester, 4% elastane ColdGear mega-grid thermal fleece fabric traps heat in tiny pockets to provide exceptional warmth. Quick-drying construction dries quickly to keep you light and comfortable, while four-way stretch fabrication allows greater mobility and maintains its shape. Antimicrobial technology helps fight odors to keep you fresher longer. The Signature Moisture Transport System wicks sweat away from the body to keep you dry. Smooth flatlock stitching and ergonomic seam placement help reduce chafing and allow for easy layering. Raglan sleeve construction provides a full range of motion in the arms for even greater comfort. Thumbholes at the sleeve cuffs seal in body heat for even greater warmth. Fitted design. Imported.