<p><b>Specification</b></p> <p>-- Length: 1.76in/44.8mm; Tail width: 0.37in/9.5mm; Head width:0.25in/ 6.3mm</p> <p>-- Laser Wave length (nm:) 640 to 660</p> <p>-- LED Type: visible red laser</p> <p>-- Power: 1-5 mW</p> <p>-- Material: Brass</p> <p>-- Sighting Range: 15 to 100 yards</p> <p>-- Dot Size: 2 inches at 100 yards</p> <p>-- Operation: Rotate the lid</p> <p>-- Temperature: -10℃ to 40℃</p> <p>-- Battery Type:6 X LR41 (Included)</p> <p>--Battery Life:  1 Hour of Battery Life Per Set!</p> <p><b>How to use the bore sight?</b></p> <p>1.Unscrew the back cap from the bore sight by turning counter clockwise</p> <p>2.Stand the bore sight on a flat surface with the laser side pointing down</p> <p>3.Insert batteries (+ side up) inside the rear opening</p> <p>4.Carefully push down and turn the screw cap clockwise to tighten the cap (the laser is now on)</p> <p>5.Place in your chamber and close the bolt</p> <p>6.To remove - open the bolt if it does not automatically extract, manually remove the unit</p> <p>7.Unscrew the back and remove the batteries to turn the unit off</p> <p><b>Package included</b></p> <p>-- 1 X Bore Sight</p> <p>-- 6 X LR41 Batteries</p> <p><b>LIFETIME WARRANTY! - Just send the product back and we'll refund you or replace with a new one!</b></p>