CODE BLACK DUCK tubes will extend out the end of your barrel 1” and have an effective range out to 60 yards. You will see patterns similar to a full constriction choke on paper, but because of the patented “stud ring” inside the tube, there is a much shorter shot string. This shorter shot string will allow more shot on target all at once. Crafted from American made, titanium infused 17-4 aircraft-quality stainless-steel and are heat treated to the optimum level for best performance. Note: Testing done by Ballistics Performance has determined that ammunition with a velocity of 1550fps and below will achieve the best results with Patternmaster Tubes. Not for use with ammunition containing flight control wad. Patternmaster's 12ga Benelli/Beretta Mobile tubes will interchange with Benelli, Sport (After 2006), Nova, Super Nova, and Super Black Eagle; Beretta A300, Silver Pigeon, White Onyx, Ultralight, and Diamond Pigeon. There are other guns that interchange as well like Stoeger 2000, P-350 Pump, and the Franchi current production guns, Legacy Escort, Huglu, CZ USA, Hatson, some Charles Daly Models, Savage, Smith and Wesson current production, and Tri-Star Phantom Field and Silver Series