A nice way to organize and associate the correct tap and drill bit combination. The top two holes labeled CNTR are made for counter-bore bits but, the rest are self explanatory.

The holes for both are a bit oversized to account for shrinkage which is why the magnet version exists. I stacked two 8mmx2mm magnets on top of each other at layer 48 and then went over them with filament before starting the drill bit holes. If you use the per-sliced model it will have the necessary pause already in it.