UA Base is a system of baselayers, numbered from 2.0 – 4.0, that takes you from cold to absolutely freezing temps. It uses a special negative grid structure to trap heat without adding bulk. Think long underwear, reengineered for athletes performing at their peak. UA Base 3.0 is built for very cold weather and moderate activity levels. Product DNA Fitted: Next-to-skin without the squeeze. UA Base™ 3.0 All Season Baselayer is extremely versatile, providing midweight warmth & mobility to a variety of activity levels & cold temperatures UA Scent Control Technology to keep you undetected in all pursuits Soft, brushed grid interior traps air against your skin, closely managing your body's microclimate to keep you warm & comfortable Material wicks sweat & dries really fast 4-way stretch construction moves better in every direction 78% Polyester/22% Elasterell Imported