The Under Armour ColdGear Reactor Womens 1/2 Zip Top is made in a Next-to-skin fit without the squeeze, ColdGear Reactor technology is intelligent insulation that adapts to your activity level for the right breathability & warmth for what you're doing. TheFabric has soft, brushed "nodes" next-to-skin for the right warmth that breathes as you move. Material wicks sweat & dries really fast. The Anti-odor technology prevents the growth of odor-causing microbes. Shaped hem delivers extra coverage & feminine silhouette. Thumbholes keep sleeves secure & help seal in body heat.