Fit & Design: 4 LED powder indicators display power bank's battery life Battery voltage: 5-Volt Power system: 2 amp 2 zippered side pockets, 1 zippered chest pocket Full zip construction Technology: Tri-Zone heating system includes 3 built-in heating panels, strategically placed on the chest and upper back to warm your core body temperature Touch-button control technology (3 settings) Additional Details: Machine washable - gentle cycle How to use: 1. Charge Up - Fully charge power banks with provided charger kit. 2. Plug-In - Connect the power bank to the USB plug located in the pocket. 3. Turn On - Press and hold the touch-button control on the chest for 3 seconds. Press the touch-button to adjust the temperature.