These aren’t your grandpa’s long underwear. Under Armour took the thermal and rebuilt it to work for athletes that take their game off-road. The unique negative grid traps monster warmth without adding excess weight and the smooth exterior allows easy layering. The Under Armour Base 2.0 Crew is UA’s most versatile thermal, built for any outdoor athlete. From running to hunting, the hill to the field, UA Base 2.0 has you covered with lightweight warmth.