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 is how I've set up my own set of Vuka Alumina bars. I put the arm cups clear of the extension clamp, so that I can rotate it down, to just touching the bar.