How to change the mode: Group 1: Choose low mode, wait about 5 seconds, when you see the flashing, turn off flashlight. Then turn on it again, you can switch to 3-mode group or 5-mode group.
Flashlight Protection explanations:
(1) Mode memory: If the flashlight is turned on more than three seconds, the current mode memoried. Turn it off and then turn it on again, it is still the original model. If less than three seconds, turn it off, then turn on it again, it goes to the next mode.
(2) Low voltage protection: When the battery voltage is 2.9~3.1V, flashlight flashes 2 times / sec, low brightness, which is a low voltage alarm.
(3) Reverse battery protection: If your battery is reversed, do not worry, no problem will occur.