1. The flashlight adopts constant voltage and current technology. 2. Do not use under excessive voltage, and the voltage shall not exceed 4.2V; 3. Do not open the circuit board by non professionals 4. In use, when the brightness of the flashlight is significantly dimmed, the flashlight (headlamp) needs to be charged. 5. Warm tips: do not direct the flashlight to people's eyes. It is super bright and dazzling, so as not to affect vision, especially children.