F3 light USB bicycle headlights 3 t6 mountain bike rechargeable light LED lights professional riding bike lights

Operation method: turn on the lights
1; First link the power cord of the lamp holder to the power cord connector;
2; Press the blue switch on the back of the light to turn it on.
Gear adjustment: In the open state, press the switch to realize low, medium and high brightness adjustment.
Double flash gear entry: press and hold the switch for 3 seconds to enter the double flash gear;
Brightness indicator description:
After the lights are turned on, the 3 indicator lights on the back of the F3 will light up, indicating that the power is above 80%.
After the lights are turned on, the 2 indicator lights on the back of the F3 will light up, indicating that the power is above 50%.
After the lights are turned on, an indicator light on the back of the F3 will light up, indicating that the power is above 20%.

After the lights are turned on, an indicator light on the back of the F3 keeps flashing, indicating that the battery is too low and needs to be charged.