I've been told there are flat bottoms (like the ones that come in the regular size protank) with 510 connections made for Protank mini 2's. Any information on where i can buy one would be greatly appreciated. I recently purchased a ZMAX MINI, its size is perfect for on the go, and the Protank Mini would be the perefect small, no worry tank for it. However the ZMAX doesn't have ego threading, I have to use an adapter which makes it stick out really far. That kinda defeats the whole small theme i'm going for. I would really really really appreciate any help you may have, thanks!!!