The Gerbing 7 Volt Vest Liner is built with Gerbing Microwire Technology that provides first-class heating performance. The vest easily slips under your jacket and over a base layer or shirt for hours of body-warming comfort. Next time you need to keep warm on a motorcycle ride around town, work in a cold warehouse or office, or are out walking the dog on a chilly day, the Gerbing 7 Volt Battery Heated Vest Liner is the one you'll grab as you head out the door. HOW TO USE: Charge Up– Fully charge 7V battery with provided charger cable. Plug-In– Connect the battery. Turn On– Press and hold touch-button control on the chest to turn on and adjust the temperature. Features: Powerful Microwire heating system includes 3 built-in heating panels strategically placed on the chest and back to warm your body Touch-button control technology Zippered front Battery Voltage: 7 Volt Colors Available: Black Material Content: 100% nylon exterior 100% polyester interior Estimated Heating Times: 100% Power (4 red/blue lights) - 2 Hours 75% Power (3 red/blue lights) - 3 Hours 50% Power (2 red/blue lights) - 5 Hours 25% Power (1 red/blue lights) - 8 Hours Includes: (1) Gerbing 7 Volt Heated Vest Liner (1) Gerbing 7V 2,600 mAh Rechargeable Battery (1) Single Wall Charger Gerbing 7V Battery Heated Vest Liner