Another version of a Tetrahedron Ring

This is a copy of version #5 (I think) of my Tetrahedron Ring series. I think I have about eight different designs for tetrahedron rings. You can see a video of more of these on my YouTube site:
Tesserak Studios YouTube Site

It's made from 1" aluminum angle stock (six pieces) and six steel hinges. Though these six pieces are not tetrahedrons, they are based on two halves of center planes through a tetrahedron, at right angles to each other. I know, that's a little difficult to visualize, but essentially what you see here could be described as the skeleton of half a tetrahedron.
Anyway, what originally interested me about this design is: here is a ring, with each hinge at a right angle to its neighbor yet with this arrangement you can get a toroidal rotation that seems to defy logic.
I don't know of any useful application of this mechanism. However it fits right into my interactive sculpture philosophy; sculpture that you are supposed to play with.

Here's a video of one of these: