Chinese bell therapy balls.
Bought a pair at Meripäivät some time ago, now I can rotate them with my off-hand splendidly, and somewhat with my right hand, too, widdershins and in reverse. It's in the thumb.
But let me tell you, these things are NOT therapeutic. Damn, I don't know what would happen if I'd do this for too long, but it would be painful.
They make a pretty sound, though. I wonder what it looks like inside.
And they bade the spedometer to read to 120, and they saw that it was hilarious.
The Chinese realized we were getting wise to Happy Meal toys and had to refine their approach.