This is a relatively simple open-top case for storing an old-style Mitutoyo 0-1" micrometer, to keep it handy in the toolbox while preventing it from banging around the other tools.
Note that this was designed to form fit a specific micrometer, so look at the photo and see if yours is the same; it is all but certain that this won't fit any other brand or size.
Print using whatever material you wish.
To add finesse, try adding some thin adhesive cork or foam rubber sheet to the underside and to the cavity where the micrometer sits.
The author marked this model as their own original creation.