The Rail Master Universal Laser Sight is an instantly-activated universal laser sight for Picatinny or Weaver rail-equipped pistols and rifles. The CMR-201 marks Crimson Trace's first universal fit laser and is built with industry-leading quality, ergonomics and fit. Rail Master Universal Laser sight fits pistols, rifles, and shotguns with M1913 Picatinny or Weaver accessory rail including: 1911 Government or Commander with Rail, AR-15/M16 or similar rail-equipped long guns, Beretta PX4 full size and compact, 92Vertec, Glock 3rd Gen 17, 19, 20, 21, 22, 23, 31, 32, 34, 35 and 38, Glock 4th Gen 17 and 19, H& K P30, 45, 45C, Ruger SR9, SR40, SR9c, SR40c, Sig Sauer P220, P226, P229, S&W M&P full size and compact, S&W SD, Springfield Armory XD and XD(M), pistols with a minimum of 1-1/16 from recoil lug.