The light is locked for shipment, refer fo Operation Instruction fo unlock.Overheat Protection:- The overheat protection device can ensure the bicycle light In a good running temperature condition, so that to protect the LEDs without burning case. If the light Is in high temperature duringoperation, It will dim the light output.Charging:- Power off.- USB PORT- Plug USB cable to USB port.- Unplug after fully charged.- Do not charge over 5V.- Keep away from flammable objects while charging.Dual Angle Beam:- Dual angle beam Is designed for user to select wide or narow angle beam for different road section.