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 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.