Two simple holders for generic micro drill bits ranging from 0.5mm to 3mm. One with 10 slots and the other with 14 slots. Recessed label sections for 4mm tall labeling strips are designed in for custom labeling of the bit sizes you would like to store.

The sliding cover snaps in place and is limited on how far it can slide so it does not fall off the holder.

The trench under the drill bit bays is to make it easier to select a bit using a pair of tweezers.

When the cover is aligned between the center of the 4th trench and the top of the 6th trench the drill bits can't fall out on their own. The cover will not slide up more than the top end of the 6th trench or pass below the bottom end of it. The pictures of the printed 10 bit version this was remixed from show the two cover positions.

Due to the tight tolerances it is recommended that you use thermally calibrated filament so you are not over or under extruded. I use these clips to calibrate my filament.
https://www.thingiverse.com/thing:1037301