Choose the low mode, wait about 5 seconds, when you see flashing, turn off your flashlight.then turn it on, you can switch to a 3 mode group or 5mode group.
Mode Memory function: if the flashlight is turned on more than 3 seconds, current mode can be memoried. Turn it off and then turn it on, still the original mode. if less than 3seconds, Turn it off and then turn it on, it goes into the next mode.
Low voltage protection function: when the voltage of the battery is 2.9-3.1V, the flashlight flashes 2times/sec with low brightness, it's a low voltage alarm.
Battery reverses protection: if your battery is reversed, don't worry, no any problem will happen.