The Under Armour Women's ColdGear Reactor Vest is a sleeveless activewear vest that is designed to keep you warm and comfortable in cold weather. The vest features ColdGear Reactor technology, which adapts to your activity level to provide the right amount of warmth. The waterproof and windproof fabric keeps you protected from the elements, while the high-visibility design ensures that you are visible in low-light conditions. With its lightweight and breathable construction, this vest is perfect for layering over your favorite activewear. Stay warm and visible during your outdoor workouts with the Under Armour ColdGear Reactor Vest.