Poor man's sea swirls?

[debbie g]

Has anybody seen this? It is a tiny piece of equipment that resembles a sea swirl, but you simply attach it to the outlet of your powerhead instead of your return. It oscillates back and forth, but appears to have no outside power from electricity. Rather, the force of the water seems to make it oscillate. Anyone know what this is called, or where you can get one?
Thanks
Debbie G

 

[dogstar]

Hydor Flo Rotating Water Deflector and Bioflo (with Aerobic Filter)
this is like what you mean?
Type that into a google search.