The Site Lite SL-500 Ultra Mag Green Laser Boresighter is the ultimate sighting-in device, used by the U.S. military and guaranteed to be the most accurate boresighter on the market. It uses an ultrabright green laser that's up to 50 times brighter than red lasers and can be seen up to 100 yards away, in full sun. Pinpoint accurate, this unit works with rifles, pistols, and shotguns alike. It fits all calibers from .22 to .50 caliber, and includes 20- and 12-gauge bores. No optional arbors are required. It comes with the SLR-100 Scope Reticle Leveler, which allows you to precisely level the crosshairs of your scope. Manufacturer's lifetime warranty. Delivers pinpoint accuracy Green laser is up to 50 times brighter than red laser Visible up to 100 yards in full sun Fits all firearms and calibers Includes SLR-100 Scope Reticle Leveler