The Bosch GHJ12V-20 Heated Jacket Kit features an enhanced modern design, lighter and more flexible material, larger pockets and more strategically placed heating elements than previous generation jacket. There is no need to layer with this warm jacket, due to three powered heating zones and a rugged outer shell that’s wind and water resistant. The three heat zones include two chest zones and one lower back, strategically placed for thorough and efficient heating. The kit includes the GAA12V-21 12V Max Portable Power Adapter, which helps users employ a Bosch 12V Max battery to deliver 2.1 Amps. This adapter also powers up many common personal devices, such as mobile devices, phones, tablets and more. Users looking for even more runtime and ability to use their Bosch 18V batteries can opt for a compatible GAA18V-24 18V Portable Power Adapter, sold separately.