Start by deciding which of the selectable mode groups, you would like to program into the light from below.
I’m going to choose mode 5 for low, medium high.
With the light off half tap to change the brightness quickly up to 20 times until the light stops responding and then Hold. The light will fast strobe once to indicate programming mode.
Release the tail cap during the first fast strobe to enter programming mode, and Hold.
Now the light will begin to blink the mode group numbers Once for mode 1 twice from mode 2, three times for mode three.
But I want mode 5 so wait until it blinks five times for mode 5 and then release the tail button again. That completes a programming process.
You can also start from the beginning, tapping the tail cap 20 times from the off position then Hold, and wait after the first fast strobe for the light to fast strobe twice. That indicates memory mode.
Memory mode allows you to choose whether the light always starts low, medium high (memory off) or remembers that last time you used it on medium and it will turn back on medium(memory on).