TubeNet

I have also heard that they are not making them anymore, though I haven't verified it. Last time I spoke to Rob from BuckeyeBrass he had some in stock and said he could get one that would work for my American shank (he only had the Euro versions in stock). Might be worth reaching out to him.

http://buckeyebrassandwinds.com/" target="_blank

I just put a new AGR on a tuba a couple of months ago. You might want to speak with Matt Walters personally.