About Laser Bore Sight Class IIIA laser; less than 5mW Light and fit .223 REM Boresight Faster gun zeroing, reduce cartridges and shells wasted Easy to sit perfectly in the bore; Sturdy brass construction High accuracy, sighting range is 15 to 100 yards 223 5.56mm Red Laser Boresighter Description 223 5.56mm Bore Sight Laser with 6 Upgraded Batteries Fit In .223 Chamber This EZshoot boresighter is perfectly fit in .223 chamber, caliber specific. Made of high quality brass material, durable and not easily deformed. Higher Accuracy Each 223 5.56mm bore sight laser has been continuously debugged to to ensure the accuracy. Help you zero in the optic within a few minutes. Save your time and cartridges and shells. Laser Bore Sighter Specifications Length 44.5mm Tail width 9.5mm Head width 6.3mm Laser Wavelength (nm) 640 to 660 LED Type visible red laser Construction Brass Sighting Range 15 to 100 yards Temperature -10 to 40 Celsius Power <5 mW Battery Type 6 X AG3 (Included) Caution: Avoid direct eye exposure to the laser. Insert the Three (3) supplied batteries into the boresigher. Negative electrode first. If you plan to store the boresighter for a long time without use, remember to remove the batteries. How to use the Laser Bore Sighter? 1. Unscrew the back cap from the bore sight by turning counter clockwise 2. Stand the bore sight on a flat surface with the laser side pointing down 3. Insert batteries (+ side up) inside the rear opening 4. Carefully push down and turn the screw cap clockwise to tighten the cap (the laser is now on) 5. Place in your rifle?¡¥s chamber and close the bolt 6. To remove - open the bolt if it does not automatically extract, manually remove the unit by tilting the rifle?¡¥s barrel upward (always practicing safe firearm practices) 7. Unscrew the back and remove the batteries to turn the unit off Red Laser Bore Sight Technical Details Color ?Yellow Style ?223 5.56mm Sport ?Hunting, Airsoft Item Weight ?0.03 Kilograms Material ?Alloy Steel Objective Lens Diameter ?5.56 Millimeters Magnification Minimum ?1 x, 6 x Compatible Devices ?Handgun Mounting Type ?Picatinny Mount Night vision ?No Item Package Dimensions L x W x H ?2.8 x 2.01 x 0.67 inches Package Weight ?0.03 Kilograms