Are these people completely retarded? I can't believe that people are actually purchasing these items on eBay. If this seller is arrested, the ATF is going to try and confiscate the items from the buyers. Furthermore, they are aluminum monocores, and it doesn't even say what kind of aluminum was used....not exactly safe. This "decorated muzzle brake" is going for $800, and is a pretty standard monocore design. It would probably be decent if it wasn't machined from aluminum. I can't believe the seller has already sold 5 of them: http://tinyurl.com/lef85xx The other two "muzzle brakes" that I found are actually from the same seller: $137 — http://tinyurl.com/lzreuls (a pretty unique monocore design concept if you ask me. Makes me wonder if it would provide decent suppression for a .22LR. I definitely wouldn't run a .223/5.56 through it) $70 — http://tinyurl.com/leyvznj (definitely seen this monocore design before, but again, made from aluminum. So probably only good for rimfire) It would certainly take some additional machine work to use these "brakes" as monocores in a suppressor, but it wouldn't be that difficult. I sent a message to the eBay seller with a link to that other guy that got arrested (Brent See in Columbiana, Ohio) for doing the very same thing. Even though a jury found him not guilty, he still got arrested, had his inventory and equipment seized, and had to pay legal fees. I don't want to see anyone else get arrested for operating in a gray area....just trying to make a buck! Not to mention, becoming a joke to the firearm community for a long time.