Looks to be a 3D printer gearbox.
Appears to fly well with a clever prerotator.
https://m.youtube.com/watch?v=qCkh-HYu2fo

This the evidence of an electric pre-rotator is the right solution hahahahah, I am kidding

I am wondering are the benefits of this double rotor ?

in my opinion it adds complexity and reduces the rotor momentum of inertia which is not really interesting in zero G ?

The only benefit I can think of is that there is an advancing blade on each side... meaning equal lift... as opposed to with the typical gyro, the advancing blade side of the disk is higher.

This model would have enormous lift, but also enormous drag? I thought gyro rotors needed to be free to rotate at the speed they want... having them geared together would not let each rotor do this? I guess one would push against the other so they run the average speed of what they want?

Nice concept.... and it works... but i don't think it would be very efficient scaled up.... interesting tho

Imagine trying to hand start those on a real machine