Assuming this is real, are there any other hoverboard prototypes yet or is this the first? A bit of miniaturization of fans and batteries and better active stab

Assuming this is real, are there any other hoverboard prototypes yet or is this the first? A bit of miniaturization of fans and batteries and better active stabilization, and this could start looking like the hoverboard concept from science fiction! Although, I don't think the problem of noise level can be resolved.