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 are ideal for the 3' shells. This is when we get our tightest patterns. This tube interchanges with Browning Invector Plus, Winchester Super X2, and Winchester Super X3 just to mane a few. Browning Invector Plus chokes fit popular models such as: Browning BPS & Maxus Winchester SXP, SX2, SX3, SX4, New Supreme & 101 models