Rings that have been possessed by the evil Dr. Eggman's robotic minions, making them slightly more...unreliable.
Just look for the telltale glow of circuitry and wires! If it's all sparkly and mechanical, it's probably not a "normal" ring.
Run. Run like the wind! Or, you know, just avoid it altogether. We don't want any more chaos in the land.
Well, technically, yes. But be warned, they might just... not work as expected. Like that one time you tried to use a toaster as a doorbell...