Up for sale is a set of Remo Spoxe from the late 80's/early 90's in great condition. These are pretty rare these days. Back in the day, Remo sold the roto-tom frames separately as a special effect. They have a clear bell sound. But can be coupled with a cymbal to get a kind of stacker effect. Or they can even be used together like a hihat. You can find some videos of these on Youtube. Terry Bozzio used them a lot.
The diameters are 5 1/2", 7 1/2", 9 1/2", 11 1/2" and 19 1/2". Also, the center hole is 1/2".