"Invisible" bicycle helmet now a product

This video isn't new and I thought of this as an unpractical design exercise. But I was wrong. Now it's on sale. (At SEK 3995 = approx EUR 400.) And apparently with the appropriate safety classification.

Personally, I don't think a helmet is very cumbersome (at least not when riding), but something similar as a wrist protector would be nice and this also means you could have knee pads which aren't on your knees until you need them.