UA Base™ 4.0 delivers heat like no other, keeping you warm even in the brutal cold. Soft, brushed negative grid interior traps hot air, providing superior warmth. 4-way stretch fabrication allows greater mobility in any direction. Moisture Transport System wicks sweat away from the body. Anti-Odor technology prevents the growth of odor causing microbes. 7.5 oz. Polyester/Elastane. Imported.