M-Audio Oxygen 49 3rd Gen MIDI Keyboard Controller
At the time of this listing, I have a quantity of these and so you may not receive the exact one shown in the pictures, but they are all in pretty much identical condition. Some yellowing of the keys but in overall good condition. This powers on with a USB cable that would attach to your computer or other electronics or charges with a USB connection. A USB cable is not included.
I found the following with an internet search:
"M-Audio audio interfaces are class-compliant on Mac, meaning no additional drivers need to be installed. If you're a PC user however, you must download and install the driver for your version of Windows. Mackie's support portal provides firmware and driver downloads for all of their audio interfaces and audio hardware."