AimSHOT Universal 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 image caliber-specific sleeve in your rifle chamber and a laser dot is projected down the exact center line of your barrel for extremely accurate scope or sight adjustment. Cartridge sleeves are meticulously engineered with precision for a flawlessly centered dot every time. These boresights by AimSHOT are an invaluable tool for any gun enthusiast, this bore sighting 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. Convenient on/off switch means you don't have to have the action closed and locked to activate the laser. A durable nylon case is included with bore sights. It is specially designed to hold your bore sight along with all the arbors you need Aimshot Laser Boresight Bore Sight .223 w/External BattBox