Graphite Coated for Long Lasting Performance in your Autoloader For Use with: Remington Model 1100 11-87 Pro Bore Guns G-3 models Beretta Shotguns Winchester Shotguns Franchi Shotguns Charles Daly Shotguns Tri Star Shotguns EAA Shotguns and many other shotguns that use a gas o-ring. For 12ga 20ga. & 28ga.