Specifications : Size(W*H)<br /><br />7.62x39MM: 11x38mm<br /><br />7.62/54MM: 14x54mm<br /><br />12G: 22x61mm<br /><br />20GA: 20x59mm<br /><br />30-06: 12x63mm<br /><br />30-30WIN: 13x51mm<br /><br />223REM: 9x45mm<br /><br />243/308w: 11x46mm<br /><br />303BR: 13x55mm<br /><br />300WIN: 13x65mm<br /><br />TLZ 762: 11x44mm<br /><br />TLZ 7MM: 13x63mm<br /><br />7mm: 13x64mm<br /><br />8MM: 12x56mm<br /><br />9MM: 10x30mm<br /><br /><br />Description :<br />Easy-to-use， self-contained boresighting  system fits in the chamber of your rifle or  pistol and projects a powerful red laser  beam aligned with the bore axis for sighting  to the point-of-aim without firing a shot.  Works with scopes， holographic red dot  sights， and variety sights. Durable，  machined brass housing looks like a  cartridge case but actually contains the  entire laser system and batteries. Insert  the batteries and screw the cap on the  housing to turn on the laser; remove the  batteries to turn off. Insert the entire  assembly into the chamber， gently close the  action， and aim at a target 20-30 yards  away. Adjust windage and elevation of the  scope or sights so point-of-aim is zeroed  on.<br /><br />Material: High Quality Brass<br />Laser Wavelength: 632-650 nm<br />LED Type: Visible Red Laser<br />Sighting Range: 10-75 yards<br />Dot Size: 1.5" @ 100 yds<br />Laser Beam:<5 mw <br /><br />Battery Life When Continuous On: 1 1/2 to 2  Hour <br /><br />Package included:<br />1 pc 9mm  Sighter Cartridge (Battery included)<br /><br />The color difference is hard to avoid in the internet sales. If you can not accept this very little difference， be cautious before you making the orders. thanks for understanding.