This was an adapter for programming inteface (USB to serial YUNA100 or BLH7840) to a old camera CGO2 or older. It has no sense anymore at Q500. CGO3 does not react to the serial connection.
I use the plugs for other purposes (cut it in the middle), i.e. to connect an SR24 receiver to the Blade 350QX to control it with ST10.
I have it with usb connected and 2 of them.. I get last end off and connect inside battery compartment cable and USB in windows computer gui software and then you can change hight motor calabration etcc