Built of 95-percent seven-ounce polyester and five-percent Elastane, Under Armour's thermal Base solution including the 3.0 Crew is ideal for maximum warmth in extreme cold. Lightweight ColdGear grid fabric is engineered to trap heat for maintaining core temperature and quick drying moisture transport, while raglan sleeves and ergonomically placed flatlock stitching ensure mobility and comfort. ArmourBlock technology stops odor-causing microbes. Available in sizes S to 3XL.