Crimson Trace LG-436 Laserguard Red Laser Sight for GLOCK Subcompact Pistols, GLOCK 19, 23, 25, 26, 27, 28, 32, 33, 36, 38, 39 POWERFUL RED LASER: Features a 5mW peak, 620-670nm, Class 3R visible red laser - the brighest beam allowed by law. INSTINCTIVE ACTIVATION: Front activation button engages the laser immediately when the firearm is held in a normal firing grip. This is the feature that sets Crimson Trace apart from the rest. OVER FOUR HOURS OF BATTERY LIFE: Powered by one 1/3N Battery (included). This product is eligible for Crimson Traces Free Batteries For Life Program. FITS Glock Third Generation 19, 23, 25, 26, 27, 28, 32, 33, 36, 38, 39. GEN4 19, 23, 26, 27, 32, 33. GEN5 19. Does NOT fit 36FGR EASY INSTALLATION: User installed- no gunsmithing required. Factory sighted at 50 feet, but is fully user adjustable for Windage and Elevation with provided tool. This model features a master ON/OFF switch for completely powering down the unit. Instinctive activation and fully adjustable for windage and elevation Manufactured to fit seamlessly with the firearm frame No gunsmithing or frame modifications required for installation Hard Polymer, Rubber overmolded front activation, master on/off switch Proudly made in the USA