12G Brass Red Laser Boresight.   Specially designed brass bore sight for 12 gauge shotguns, made of solid premium brass for snug barrel fit. It adopts a 635-655nm visible red laser with safe power below 5mW, offering clear aiming dot from 15 to 100 yards. The laser dot is 1.5 inches at 100 yards for easy optic alignment. 163g solid brass construction is durable and stable during calibration. Simply insert it into your shotgun barrel to finish pre-zeroing and save shooting ammo.