Beamshot RF9 Mount: Attaches to All Rifles, Shotguns & Airsoft Guns to Create a Standard 1913 Picatinny Rail System Which Will Accommodate All Types of Laser & Flashlight Accessories The BEAMSHOT RF9 mount Creates a standard 1913 picatinny rail system on bull barrel long guns Included in the RF9 kit are 4 different size spacers Fits on all round barrel type firearms; Ideally suited for 12, 16, 20, 28 gauge shotguns and all kinds of rifles Makes it easy to mount Beamshot laser sights, tactical flashlights and other types of accessories on your firearms