NWT Men's size Small or fits Women's Medium Black Fleece Heated Vest, Washable Includes 7.4 Volt chargeable battery pack as pictured See all photos for product information. The vest is not bulky and you don't notice the 6 carbon fiber heating elements that generate heat across the core body areas (left & right shoulders, mid-back, left & right pockets, collar) and 3 heat levels for adjusting by pressing the button. (3 hrs on high, 6 hrs on medium, 10 hrs on low heat) Type-C charging port enable heat to vest and charge your phone at the same time. heats quickly in seconds w/ 7.4V battery.