Designed specifically for use in glock 42 pistols the lms-g42 replaces glock's factory spring guide assembly with a high intensity red laser sighting system for advanced target acquisition.Easily user-installed without the need for gunsmithing or special tools the guide rod laser is constructed with rugged precision components including aircraft-grade aluminum and genuine wolff springs.Power Switch: Ambidextrous On/OffWavelength: 650 nmDot Size: N/APower: 5mWWeight: 0.62 ozBattery: 377 (4)Laser Color: RedFirearm Fit: Glock 42Finish: StainlessMount Type: Guide Rod