Half a sculpture. The two parts are connected by ten 3/16" spheres which you'll need to source. Ball bearings will work fine; I'd recommend gluing them to just one half so you can see the design both together, and with the interesting cross-section exposed. In steel, you can use magnets!
You can also get the whole kit from my own site here.
Here's a button to get both halves: +
Lastly, here's the unsplit version.