This file is a simple replacement for the extruder cover plate in the reverse bowden system designed by DocWeebl ( https://www.printables.com/model/465985-magnetic-reverse-bowden-system )
Simply replace the extruder cover plate in that design with this one.
I printed all my parts with PETG at .15 quality. the model is designed to be printed on its side with a very narrow support in the middle of the magnet retention ring. I found this produced the best end part.
The author remixed this model.