The Vuka Alumina lineup isn't merely an entry-level version of Zipp's other bars. It's a re-think of their original system, it stands on its own, and has some very smart design features. There's more adjustment here than you see in any other clip-on bar system, yet Zipp keeps the hardware fairly minimal, easy to adjust, and aesthetically pleasing. The Vuka Alumina Clip is a chameleon. You can set it up to look like almost anything you want, creating almost any imaginable relationship between cups, extensions, and the base bar.
This setup is on the extreme side, but shows what you can do with the risers, tilt adjustment, etc. Want to test out a TJ Tollakson high-hands setup? It's no problem for the Vuka Alumina.