These work as described but be warned that the instructions are not ready for prime time and there is absolutely NO support after the sale. I've emailed them a dozen times with questions and never received an answer or even an acknowledgement of my questions. Bad form for something this expensive.

great idea however REELights are about half the price and althought an extra couple of magnets to fit just as good, these are just too expensive , basic lights cost less than 5 euros

If, despite all the potential pitfalls, autonomous vehicles are going to be let loose on our roads, as seems likely, then I suspect that it will be necessary for all road vehicles, including bycycles, to transmit their precise location to all nearby autonomous vehicles as a back-up should any vital sensors on them fail, making them partially sighted.
This transmitter will need an electrical supply, as do bicycle lights (which should be on whenever the bicycle is on the move), It would make sense for all bicycles to legally required to have something like what used to be called a dynohub to provide this electrical supply.
Related to this subject is the desirability for all bicycles to transmit a pulsed, eyesight safe, laser beam to the front and to the rear that all other road vehicles can detect (like those sold to pilots and hill walkers, etc. should they need to be rescued, which cannot happen if they cannot be found). What they do with the knowledge is for others more expert in the field than me to decide.
We need to be preparing for autonomous vehicles now, especially their relationship with bicycles. Leaving it to the inevitable inquests will be too late.

An interestingly engineered product, somewhat over-hyped in description. It is simply fitted by the user, generates lighting power from wheel motion and incorporates sufficient capacitive energy storage to cover pauses at traffic lights. Its expensive and on the "..don't want the friction of a dynamo slowing you down.." statement, it's worth noting that the drag created by its relatively inefficient generator arrangement will be greater than that for most hub generators.

Back in Victorian times, lamps for cycles, or other, were available that required no batteries, and also did not require contact with the wheel or tire. They were called acetylene lamps, and ran on water and carbide. They also flashed, or rather flickered a bit.

DId they just invent a perpetuum mobile? Bye bye 2nd law!

Seems like a better idea would be to include a battery that is always charging night and day. Then run the light off the battery.

In all the applications I know about Eddy currents (https://en.wikipedia.org/wiki/Eddy_current) are avoided. The core of a transformer uses thin layers of metal to minimize them. https://en.wikipedia.org/wiki/Transformer#Energy_losses
Léon Foucault demonstrated Eddy currents by spinning a copper disk in a magnetic field to show the direct conversion of mechanical energy into heat. But for this light to work Eddy currents are used to magnetize the rim and that magnetism is used to turn the shaft of the internal generator. https://www.google.com/patents/US20140132155
I think the prior comments about using a hub generator would result in a more efficient way to get some electrical power.

I hope they have great "locking" hardware since they would be a prime target for thieves that want bicycle BLING...

Power to run the light must be extracted from the wheel.