Under Armour 2.0 Base Crew - Men's: Fitted: Next-to-skin without the squeeze. UA Base(TM) 2.0 is highly versatile mid-weight protection for colder conditions & a variety of activity levels 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