Sight Block cut to fit any 9mm Glock. Replaces the thread protector on standard-length threaded Glock barrels (Glock 17, 19, 34, 17L). Includes vial of high-temperature thread-locking compound (no set screws are used). Picture at right shows a Glock 43 rigged with a low-profile sight block. The low-profile version matches the Glock 43 slide profile -- and is slightly narrower than a typical 9mm slide.