Yeah, it threads into the choke threads. And the baffle design must accommodate the huge potential for baffle strikes with a shotgun load. Maybe it's some sort of barrel extension with holes that bleed the gases into the baffles? I really don't know anything about previous shotgun silencer designs. But knowing SilencerCo, I'd be willing to bet that their design is new and different from other previous attempts to design shogun silencers.
0331: "Accuracy by volume."