For maximum warmth in brutally cold conditions, the Under Armour Base 4.0 Long-Sleeve Crew Shirt can’t be beat! Mega-grid thermal fleece fabric – a 92% polyester, 8% elastane blend – dries quickly to keep you drier, lighter, and more comfortable than ever before. An ArmourBlock antimicrobial treatment helps reduce odors, ensuring that you stay fresher longer. The thermal grid interior traps heat in tiny pockets for long-lasting protection. Lightweight, four-way stretch construction offers improved mobility and maintains its shape. Ergonomic flatlock seams help reduce chafing and allow for easy layering. This essential ColdGear baselayer top features a classic crew-neck collar, raglan sleeve design, thumbholes at the cuffs, and a slight drop-tail hem for added coverage in back. Fitted design. Imported.