UTG 126 Lumen Combat Xenon Light, Handheld and Ring Mount Constructed of aluminum Includes pressure switch Ultra high 126 lumen output Weapon-mount tactical flashlight with long-lasting Xenon bulb Ultra-high 126 lumen output; combat tactical front head Pushbutton momentary switch and twist-on permanent switch.Remote pressure switch; mounts to Picatinny/Weaver rails Easy-to-hold body for handheld applications; measures 5.22 inches long Refer page 7 of instruction manual for installation instructions