LaserMax Model LMS-G42, Laser, Fits Glock 42, Guide Rod Laser LMS-G42 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 a stainless steel tube.