Wheeler Professional Laser Bore Sighter with Magnetic Connection, Multiple Caliber Usage and Storage Case for Scope Mounting, Gunsmithing and Maintenance SPECS: Class IIIR with power output of less than 5mW EASE OF USE: Magnetic connection quickly and easily attaches to the muzzle of the gun and can be used on any caliber rifle or handgun RELIABLE: Laser module permanently secured for dependable performance and hand-tuned during manufacturing to ensure accuracy DURABLE: Machined aluminum body with soft rubber overmolding INCLUDES: (1) lithium 123A battery, (1) reflective sighting grid, (1) plastic storage case