These are sort of neat. They’re rubber bands shaped like a wireframe cube. They keep their shape, but of course they stretch since they’re rubber bands. They’re easy to find in a drawer, and we suppose that’s it as far as their advantages are concerned. And here come the disadvantages, or rather the disadvantage: it’s $10 for 3! They’re 20mm per side, if you must know, though to be honest if you end up buying these we have something to tell you: you have too much disposable income!