Useful for initial sighting your pistol, or as a training aid for “quick draw” drills, the Sightmark .44 Magnum Boresight offers a quick and easy way to sight in your .44 Magnum pistol. Range for sighting is 15-100 yards, with an operating temperature at -10 to 50 F/C. Includes a carrying case and three (3) AG3 batteries.