UA Base 2.0 is built for cold weather and high activity levels. It uses a unique pattern that's designed to trap heat without adding bulk. Think long underwear, revamped for today's top athletes. UA Base 2.0 Active Baselayer is lightweight, flexible & breathable for high activity in cool conditions. UA Scent Control Technology to keep you undetected in all pursuits. Soft, brushed grid interior traps air, managing your body's microclimate to keep you warm & comfortable. Material wicks sweat & dries really fast. 4-way stretch material moves better in every direction. Performance elastic waistband.