User Manual: 1. Find out the USB charging port from the pocket of heating jacket, plug it in the power bank, the white light will flash and the garment will enter system self-check mode. 2. Hold down power button for 3 seconds to start the system, which will then run a heating cycle (red, blue, green), after that the garment will start heating on high power continuously for 5 minutes before automatically switching to medium power. There are three thermal levels to change the heating (red - high power 98% thermal output, blue - medium power 75% thermal output, green - low power 50% thermal output) 3. To turn off the system hold down power button for 3 seconds.