Carlson's 12 Gauge Right Handed Auto Catcher is an all-steel shotgun shell catcher that prevents empty hulls from being ejected through the receiver opening on semi-automatic shotguns and holds the empty hulls for easy removal. One model works with all 12-gauge semi-auto shotguns. Save your hulls from distracting you or others at the range while keeping empties from hitting the ground. Simply peel off the double-faced tape, 2 included with the auto catcher, and attach to the gun's receiver. The semi-permanent adhesive can be removed if desired. The softly padded tape acts like a barrier, keeping the metal plate away from the gun. There is no movement or vibration to scratch the receiver's finish. The auto catcher can be adjusted to fit different shotshell loads and guns where needed.simply close or open the ends of the wire with no modifications to the gun.