Xtreme Lumens Tactical Weapon-mounted Light - Long GunThe TWM 852XL Xtreme Lumens Tactical Weapon Mounted Long Gun Light uses a CREE LED rated 850 lumens for 1. 75 hours providing a beam distance of 245 meters. The rear facing single switch provides both momentary and constant on lighting operation. Designed to securely attach to a long gun picatinny rail, the IP X7 rated waterproof housing is constructed from aircraft grade 6061 T6 aluminum. The TWM 852XL comes preinstalled with one set (2) cross rail