Crimson Trace Glock Gen3/Gen4/Gen5 Compact Red Lasergrips - Black - LG-639 Lasergrips are a rear-activated laser sight for GLOCK Compact pistols. Featuring Crimson Trace's famed Instinctive Activation, which allows the laser to be activated with a normal firing grip, the LG-639 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. Activation Location: Rear Activation Activation Type: Instinctive Activation Attachment: Grip Attachment Beam Intensity: 5MW Peak, 633NM, Class 3R Red Laser Dot Size: Approx. 0.50in At 50ft Fits Glock Gen3 19, 23, 25, 32 Gen4: 19, 23, 32 And Gen5: 19 (Will Not Fit 19X)