Fit and Design: Comfortable, stretchy, and soft fabric easily moves with you Easily change the heat settings with the tap of a button 92% polyester and 8% spandex Technology: Powerful Microwire heating system includes built-in heating panels strategically placed on the chest and upper back Touch-button control technology 7 volt battery Additional Details: HOW TO USE: 1. Charge Up– Fully charge 7V battery with provided charger cable 2. Plug-In– Connect the battery 3. Turn On– Press and hold touch-button control on the chest to turn on and adjust the temperature 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 Base Layer Shirt (1) Gerbing 7V 2,600 mAh Rechargeable Battery (1) Single Wall Charger Gerbing Lifetime Warranty Machine washable/gentle cycle