Tristar says Beretta/Benelli Mobil chokes. However, I found out the hard way that there is a difference. I ordered a MOD for a .410 Cobra from MidwayUSA and the thread was different. When I called Tristar to tell them about the issue they kinda blew me off. They said they might have some chokes re-stocked later in March. This is what I read in reviews on a MidwayUSA "reviews" thread: "The factory (Tristar) says their choke tubes are the same Beretta/Benelli Mobil chokes. They are not. The thread pitch is the same, but the thread pattern is not. Tristar chokes have common "V" threads and Beretta/ Benelli thread are rounded"... I returned the choke for a refund. Perhaps William from Sumtoy could chime in on this thread, better explain it...