Once you remove the front sight a fake can designed for the Beretta Storm carbine slips on perfectly and mounts flush with the front end of the barrel. These are held in place by setscrews, and they provide no protection for the threaded end of the barrel (although the threads are completely covered by the can) so they aren't perfect, but they look good and give the illusion of a shorter barrel. I just remove the can and clean the threads after using corrosive ammo...don't know if it's essential, but it's easy enough to do.
Sorry, I don't remember the manufacturer of the fake can...I had it in a box of assorted junk for years, just happened to come across it and tried it out.