A wavy molded polyethylene surface sits atop a base that can be used indoor or out. The surface then rocks back and forth over the base, testing your balance. It's $684 and a helmut is not included. In fact, the carpet for the Flying Carpet is not included. That's an extra $382.
It doesn't literally fly. But the Magis Flying Carpet, designed by Eero Aarnio, does rock. Admittedly, not a necessity you must register for, but the Flying Carpet is fun.