Emailed YHM about getting a new piston for my Cobra so I could put on my Sig and this is what I got back. Sir, Unfortunately I have bad news. We were finially notified by ATF Monday morning that we can no longer sell individual pistons, 3-lug adapters, fixed barrel adapters and most other componets seperately. We can sell a sound suppressor with one attaching device and that is it. We are not very happy to say the least. This is going to affect our business tremendousely. Apparently we were the first, and now ATF is going to go after all other sound suppressor manufacturers as well. We are going to fight this, and the owner of this company has already contacted some attorneys about taking legal action. As you saw we were forced to take all the products off our web page or face legal action by ATF. We are waiting to hear the final word on the QD mounts, and I am not expecting good news about them either. All I can tell you now is to be patient while we appeal ATF's ruling and hopefully get it overturned. Sorry for the inconvience, however our hands are tied at the moment, and no one is more upset than us over this matter.