CRIMSON TRACE LG-637 LASERGRIPS RED LASER SIGHT FOR GLOCK GEN3, GEN4 & GEN5 FULL. LG-637 Lasergrips® are a rear-activated laser sight for GLOCK Full-Size pistols (Third Generation 17, 17L, 22, 24, 31, 34, 35, 37, Gen4 17, 22, 31, 34, 35, 37 and Gen5 17, 19X, 45). Featuring Crimson Trace’s famed Instinctive ActivationT, which allows the laser to be activated with a normal firing grip, the LG-637 includes a Master On/Off Switch for completely powering down the unit. User-installed in moments by attaching securely to the gun frame, this laser sight is fully adjustable for windage and elevation. Provides 4 hours of run time with (2) included 2032 Lithium Batteries. FITS GLOCK THIRD GENERATION 17/17L/22/24/31/34/35/37, GEN4 17/22/31/34/35/37 AND GEN 5 17, 19X, 45. 5MW PEAK, 633NM, CLASS 3R RED LASER. 0.50 AT 50.