If that is the case, there are even 5 versions altogether.My rba says on the side "Kanger Tech Mini rba Plus"
I understood that the original RBA has small slots in the base and the cap threads on to the base. The V2 has larger slots. The Plus has no slots in the base, holes on the side and a screw holds the cap to the base.
Maybe this applies to the full size Sub tank and not the mini. I don't know.