Designed specifically for use in Glock 19 (Gen5), Glock 19 MOS (Gen5) and Glock 19X and Glock 45 pistols, the LMS-G5-19G replaces Glock&';s factory spring guide assembly with a high intensity green 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. Automatic 10-minute time-out mechanism prevents accidental battery drain.