Huh? It allows you to move the mirror in the X and Y direction. What else would you call it?
Of course they're not the same as an MM1. No one suggested that those mounts were suitable for dichros... But just about every bounce mirror I've ever seen uses some variation on the standard "U" shaped mount. (Spring-loaded mounts do not have enough adjustment to be used effectively for bounce mirrors by themselves, and combining a U-mount with a spring plate is both expensive and heavy.)
As I mentioned earlier, DZ has a few of these mounts , and he didn't have any problems aiming them. He has already posted the details (including pictures), and told us how pleased he was with them.Maybe somebody who buyed one can give us details?
Adam