Oh, yeah.. those were making the news a couple months ago.
It’s one of those ‘why didn’t someone come up with that sooner’ ideas. It’s tethered flight, sure, but it’s remarkably inexpensive, since you don’t need expensive fuel and propellants. You can stay aloft functionally indefinately, unlike other jetpacks which have a flight time that is measured literally in seconds. Awesome for vacation areas, as shown, since it’s cheap enough that anyone can give it a try.