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. This tube interchanges with Benelli Crio, Beretta Optima Plus, just to name a few.