PowerTac E5 Gen4 980 Lumens CREE XM-L2 LED Flashlight Firefly and Strobe with two LegionArms CR123 Batteries Utilizes a CREE XM-L2 U2 latest LED that enables the E5 to produce an amazing 980 lumen at the brightest level and strobe setting The E5 also serves as true tactical light that can be weapon mounted or hand held Power on/off switch press the push button half way for momentary on To switch functions, turn the light on and press the side switch and release immediately The flashlight will access the mode last used