We have finally found him but still the net and even bought the same.
The operation is self-explanatory.
Poke plug and the rest is for the "emulator" ... in our case Dolphin on the PC.
Full support of the original GC controller on PC in conjunction with the Nintendo GC games.
The adapter works reliably and without errors In addition, he has a pretty robust housing and the connecting cable (USB), with its 1.5m more than long enough.
Too bad that you can connect to the adapter only 2 GC controller, therefore you need to buy as a forced family of 4 2 adapter.
In short .. the purchase was worth it.