Combining 100g of premium PrimaLoft warmth-holding insulation and a front and back battery-powered heating element, the H.E.A.T. liner vest has got you covered. The Tri-Zone heating is selectable for three levels of customizable heating, so dial-up what you need when you need. Use the integrated iPhone charging cable to keep your phone ready for those post-hunt pics. Elastic cuffs and adjustable drawstring waist keep the warmth in. - 100-g PrimaLoft silver premium insulation. - Windproof shell fabric with Durable Water-Resistant (DWR) finish-Tri-zone heating with two elements in the chest and a large back element. - Integrated iPhone charging cable accessed in a zippered chest pocket. - Warmth-sealing elastic cuffs. - Two zippered hand pockets. - Two zippered chest pockets- Adjustable drawstring waist. *Batteries sold separately BANDED H.E.A.T. Battery Info: Banded H.E.A.T. handwarmers, Jackets and Vests use a 2 USB Port battery (1 port for heating element, 1 port for phone charging) — Only (1) ONE battery is needed to operate the Banded H.E.A.T. Jacket, Vest and Handwarmer. Any 2 USB port power pack will work, we recommend the battery option linked below from OtterBox.