Whether layered or by itself, the Under Armour Boys' UA Base 2.0 Crew is the perfect choice for active days outside in cool temperatures. Made of 4.7-oz., polyester/elastane fabric, this shirt is warm, comfortable, and great for all day wear. UA Base 2.0 delivers highly versatile mid-weight protection for colder conditions and a variety of activity levels. The Moisture Transport System wicks sweat away from the body, so you stay dry and light even during intense endeavors. 4-Way Stretch fabrication allows greater mobility and maintains shape, so you will always be at the top of your game. Anti-Odor technology works to prevent the growth of odor causing microbes, keeping your shirt and you smelling fresher for longer. Imported.