This is a well known parallel graphics interface for Commodore 64 and Vic 20 and it is listed as a successful piece of hardware for implementation with the retro printer project. See the last photograph for the website of retro printer and go there to read more about it.
Retro-Printer compatible :)
You receive the MW350 vintage parallel graphics interface that is clean and has dip switch settings information on the front and all three cables as shown you do not receive the retro printer hardware
Enjoy