Designed specifically for use in Glock 17 Gen5 Glock 17 MOS Gen5 and Glock 34 MOS Gen5 pistols the LMSG517 replaces Glocks 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 aircraftgrade. Automatic timeout after 10 minutes prevents inadvertent battery drain.