Greg Black Bass trombone mouthpiece

[56Alfa]

Hi,
I currently have a Greg Black OG medium.
I was going to order a 2 piece Heavy OG.
Does any one know if the 2 piece heavy OG rim is interchangeable with the other 2 piece bass trombone GB mouthpieces?
If not what is so special about the 2 piece?
Thanks,
Mike

[Slideorama]

Greg would know.
Call him up - 980-277-8195.

[GabrielRice]

What's special about a 2-piece mouthpiece is that you can get multiple cups for the same rim. If you don't need to do that, there's no reason to have one.