Okeba Red Dot Accurate Laser Bore Sighter Boresighter Collimator for 0.22 to 0.50 Caliber Cartridge Sights & Riflescopes Accurate laser bore sight collimator Suitable for any 0.22 to 0.50 sights and riflescopes More convenient and accurate than scope and sight alignment Allows you to instantly and accurately set your sight or scope Comes with 4 bore adapters, one screwdriver, and three pieces of battery