UTG 23mm IRB Xenon Pistol Light w/ Integral Mounting Deck Xenon light bulb or IRB that has the advantage of higher maximum lumen output and better focus at longer distance Can be mounted on pistol for pistol applications Includes a mounting mechanism for easy mounting on most tactical pistols and firearms with or without rail slot Ambidextrous rotary switch for permanent or momentary on/off Battery Type: CR123A Lithium Battery X2