All of mine predated the ABC era, had steel liners, so I suppose the rings were iron ones. I had some different versions. Most seemed to only have a single BB, at the rear end, although one of mine came with a front BB as well. They vibrated VERY little, unlike the Max-S 35s, which vibrated "some".
I've had three Max-H 40s, and a couple of H-35s. The 40s I had were very nice for stunting, with a lovely 4-2-4 break, and good power. All could fly a 35-size stunter in a rich enough 4-stroke that you seldom broke to two-stroke, and only then, when you REALLY needed it, much in the way I loved to use Tigre G21-46s, although the 4-stroke rpms were too high for 11-6 props (which were my choice for the G21-46s), and I used 11-5s for my Max-H 40s. One of my H-35s probably was a "Combat Special", not clearly marked as such, and wouldn't run in a breaking run at all.