Crimson Trace Corporation Black Finish, 150 Lumen Light, Fits Glock 17/19 3rd 4th and 5th Generation, Black Finish, 150 Lumen LED, Red Laser, User Installed, Instinctive Activation, 4 Modes 01-6940-1 LL-807 Laserguard(R) Pro for GLOCK(R) Full-Size and Compact pistols is a powerful red laser sight and 150 Lumen LED white light in a single compact unit. This illumination and targeting product is activated with Crimson Trace's famed Instinctive Activation(TM)" which activates the unit via a front activation button when the pistol is held in a normal firing grip. The LL-807 features four modes of operation (see below)" a Master On/Off Switch" is completely user-installed in moments with no modifications to the gun frame and the laser is user-adjustable for windage and elevation. Offers 2 hours of battery with a single CR2 Lithium battery. This model will fit the following GLOCK pistols: Third Generation G17" G17L" G19" G22" G23" G24" G25" G31" G32" G34" G35" G37" G38" Gen4 G17" G19" G22" G23" G31" G32" G34" G35" G37 and Gen5 G17" G19" G19X" G45.