Re-profiled sight block, cut down to fit any Glock .40. Replaces the thread protector on a standard-length threaded Glock barrels (Glock 22, 23, 24, etc.). 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 .40 slide.