A simple holder for micro drill bits (10 sizes) ranging from 0.5mm to 3mm. This one has been specifically designed for the 30 piece Warrior Brand High Speed Steel Micro Bit Set.

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 0.8mm trench and the top of the 1.00mm trench the drill bits can't fall out on their own. The cover will not slide up more than the top end of the 1.00mm trench or pass below the bottom end of it.

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