Ask The Brewmasters

It almost looks like a garola fitting.  If you put that into Google, it should give you some pictures to compare it to .

Also looks just like the one on the Della Toffola I operated for many years. I rethreaded that bolts many times.

Oh boy, that looks like an old Spadoni filter! We have a DCBL 100 from 1995 and that part is labeled "clamp" in the manual that is crudely translated from Italian. Probably not much help. If you're looking to replace it you could try Prospero - they have supplied Spadoni parts for us in the past. Or if you just want to identify it you could say "clamp" with a fancy Italian accent.
Hope that helps!
Jim