The Aimshot Laser boresight is the most complete, accurate, easy and inexpensive way to accurately boresight your weapon. Just slide the aimshot laser boresight cartridge into the caliber-specific sleeve in your rifle chamber and a laser dot is projected down the exact centerline of your barrel. Cartridge sleeves are meticulously engineered with precision for a flawlessly centered dot every time. An invaluable tool for any gun enthusiast, this boresighting unit will save time and ammunition while allowing you to sight your weapon in areas where discharging a firearm may not be possible and takes up no more space in your pocket than a rifle cartridge. A durable nylon case is included with bore sights. It is specifically designed to hold your bore sight along with all the arbors you need. Arbors are sold separately. 5 year limited warranty. Minimum sighting range: 3 yards,Maximum sighting range: 100 Yards, Battery Life: 20 minutes continual.