Calibrate your targeting to hair-splitting accuracy with a Sightmark Magnetic Universal Boresighter. Finding your targeting system isn't quite hitting the mark like it used to? Don't replace... re-calibrate! Simple magnetic mount means you can attach and remove the Sighter in seconds. All you do is place the base onto the end of the barrel and a red laser dot will show you exactly where your aim will land the shot. From there, you can adjust your scope or sights... saving time, money and frustration!