<b>Specification</b><br> -- Length: 64mm; Tail width: 12mm; Head width: 7mm <br> -- Laser Wave length (nm:) 635 to 655 <br> -- LED Type: visible red laser <br> -- Power: <5 mW <br> -- Construction: Brass <br> -- Sighting Range: 15 to 100 yards <br> -- Dot Size: 2 inches at 100 yards <br> -- Operation: On/Off End Cap <br> -- Temperature: -10℃ to 40℃ <br> -- Battery Type:3 X LR41 (Included) <br> <br> <b>How to use the bore sight?</b><br> 1.Unscrew the back cap from the bore sight by turning counter clockwise<br> 2.Stand the bore sight on a flat surface with the laser side pointing down<br> 3.Insert batteries (+ side up) inside the rear opening<br> 4.Carefully push down and turn the screw cap clockwise to tighten the cap (the laser is now on)<br> 5.Place in your rifle’s chamber and close the bolt<br> 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)<br> 7.Unscrew the back and remove the batteries to turn the unit off <br><br> <b>Package included</b><br> -- 1 X Bore Sight <br> -- 3 X LR41 Batteries <br>