Designed specially for 3″ shells. Product Description Patternmaster concept is that the “studs” inside the choke grabs the base of the wad as it passes through while the front of the wad is flush with the front of the tube. Long range tubes used with 3″ or 2 3/4″ shells will give you the tight dense pattern that Patternmaster is known for. Shooting 3 1/2″ shells through the long range tubes will produce a modified pattern. Patternmaster’s 12ga Benelli/Beretta Mobile tubes will interchange with Benelli M1, M4, M3, Sport (After 2006), Nova, Super Nova, and Super Black Eagle; Beretta A300, Silver Pigeon, White Onyx, Ultralight, and Diamond Pigeon. There are other shotguns that interchange as well like Stoeger 2000 Semi-Auto, P-350 Pump, and the M3500, Franchi current production shotguns, Legacy Escort, Huglu, CZ USA, Hatson, some Charles Daly Models, Mossberg Silver Reserve, Savage, Smith and Wesson current production, Traditions Semi-Auto, and Tri-Star Phantom Field and Silver Series, just to name a few. For more information about your shotgun interchange please see the firearm owner’s manual or contact the firearm manufacturer.