I bought this blindly hoping it was what I was looking for. My use for this was to be able to extend my Arduino Mega/Uno, which I built for a Christmas garland controller, into a host computer. Setup: The computer is about 75 feet from the near controller I have. I know USB can reach that distance, but I wanted another option. I wanted to attach one of the IP68 ethernet ports to the control box, plug it into a socket in the box and connect USB A to B. On to the Arduino. Then connect an ethernet cable to the controller box from the outside and connect it to a computer using another ethernet female-to-female adapter. The control unit's Ethernet cable connects to the FxF adapter and the second of these connectors connects to the other end. Then use USB AA to connect to your computer. This of course allowed me to communicate with the Arduino over the ethernet cable. Maybe it's not what it's used for, but it worked for what I needed.
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