Umm....last time I checked (and this may be different now) Dive Rite was built in FL, Promate overseas. When you open up a Promate, they vaguely resemble a Sherwood- shimms etc. Now, the second stage being generic, the covers fit, I think, but that doesn't mean too much. As for my experiences, I ended up with a set, they were awful. If they weren't freeflowing they were hard breathing, no matter what we did to them. Had another buddy that ran the same problems. BTW, I never truely used them, just in a pool, way too cappy in my opinion to use in real water.
-J
-J