3-stage output, press and hold the switch slightly within 1 second for mode change. If you find a mode you like, press to lock on. If you leave on for more then 1 second this light has a "Mode memory". Next time you turn it on, it remembers the last mode.
Low(0.8%,1.8 lumens)--> Medium(15%,35 lumens)-->High(100%, 300 lumens).
Input range: 0.9~4.2V
Battery type: 1AA/2AA/3AA/CR123A/RCR123