Function: ---This laser bore sight is designed for sighting in your rifles and pistols. ---There are 9 bore adapters, can be applied to all .177-.54 caliber rifles and pistols. --- By projecting a laser beam from the center of the barrel axis of your firearm, this laser bore sight collimator allows you to instantly and accurately set your sight or scope. Specifications: Material: Aluminum Length: 6.3inch Head diameter: 0.62inch Tail diameter: 0.2inch Laser wavelength: 630-680nm Max. Output Power: ＜5mW Laser class: IIIA Color: Red Weight: 1.33oz Package weight: 4.7oz Specifications of adapters [Adapter 1]: .170 to .177 cal [Adapter 2]: .220 to .25 cal [Adapter 3]: .264 to .284 cal [Adapter 4]: .300 to .320 cal [Adapter 5]: .338 to .358 cal [Adapter 6]: .375 to .410 cal [Adapter 7]: .416 to .450 cal [Adapter 8]: .458 to .460 cal [Adapter 9]: .500 to .540 cal Package Includes: 1 x Laser boresighter 1 x Screwdriver 1 x Allen Wrench 1 x Spare Screws 6 x LR44 Batteries