The Prusa enclosure addon for the buffer uses their standard 20x6x2mm magnets, however this size is not readily available like the 20x5x2mm version that you can find all over Amazon. I modified the slots to accommodate two of these magnets because they are not quite as strong as the Prusa version, but two combined per slot does the trick.
Forewarning, the magnets fit TIGHTLY, so use your bare hands to get them started, but use something else for leverage to drive them the rest of the way. For the small plate holders, I used the part itself for leverage against the flat surface of my table (see photos) There isn't much room to work with without redesigning all the parts related to the buffer, so the size is what it is.
Filament that I used:
Elegoo Rapid PETG - Black
Settings that I used:
0.4mm nozzle
0.2mm layer height
5 top layers, 3 bottom layers, 2 perimeters (min)
20% grid infill
No supports
Magnets I used:
https://www.amazon.com/gp/product/B0B6PQPBP1/ref=ppx_yo_dt_b_asin_title_o03_s00?ie=UTF8&psc=1
The author remixed this model.
Modified magnet slots to accommodate two 20x5x2mm size magnets per slot.