Introduction:This boresighter is designed for sighting in your shotguns without firing a shot. Simply install the included batteries， place the entire assembly into the chamber， and gently close the action. The sight will emit a straight red laser beam， providing precise reference for zeroing in your sights or scopes.Features:Fits 12 Gauge Shotgun chambersLight weight and durableWorks with any sights (iron， optical， laser， holographic， etc)Windage and elevation adjustableLong sighting rangeSpecifications:Material: CopperLaser wavelength， 632-650 nm.Sighting range， 10-75yards.Dot Size: 1.5" @ 100 ydsSize: 60*22mmColour: As picturesNet weight: approx 50g.Package included:1x Boresighter4x AG13 Battery