This model is the same as Area51's remix of the original MMU2 Selector, but the hole has been enlarged to fit a 6x10x2mm magnet. I had a couple of these left over from ‘S’ upgrade kits.
I used the PrusaSlicer negative volume feature to cut the hole for the magnet, so there are no other source files.
Follow the Prusa guide for printing MMU2 parts for the proper settings.
The author remixed this model.