GRG .223 5.56x45mm Caliber Cartridge Laser Bore Sighter Boresighter + 20 Gauge GA Arbor Sleeve Class IIIa 635nM Less Than 5mW Avoid Direct Eye Exposure to Beam Precision Laser Optics Sits perfectly in the .223 Chamber and Arbor Sleeves for 20 GA Shotgun Class IIIa 635nM Less Than 5mW No more wasting ammo