The Site-Lite Laser Bore Sighter uses the latest laser technology to provide superior boresighting accuracy. Super-strong magnets in the arbor securely centers the laser within the muzzle for consistent accuracy. A unique system of adapters and O-rings fit 22 to 50 caliber handguns and rifles, 20 and 12 gauge shotguns and muzzleloaders. To boresight, level the scope with the included Scope Reticle Leveler and Leveling Target. Then input your specific rifle and ammo data into the included Ballistic Targeting System software program to create a custom laser boresighting target. Next, place the laser spot on the target, align your scope with the target crosshairs and you're boresighted for up to 300 yards.The SL-100 is ideal for the average hunter. Using just two button cell batteries (included), they will last up to 1 hour (continuous use). The SL-100 uses the latest laser technology to provide superior boresighting accuracy. Super-strong magnets in the arbor securely centers the lase...