Can't get a picture right now, but the black USB device that plugs into the computer has tow inputs.
One is the JR looking pigtail extension, and the other is a hole in the black plastic part of the device.
[The short colored cable is needed because JR/Spektrum use an optical converter in the Tx]
That short cable just looks like two wires and two connectors.
What is so special about it, and where is the converter?