These are a set of press-fit cases for Raspberry Pis with a very slim profile.
For each Pi model, there's a bottom and two tops. One top has openings for the I/O pins; the other does not. The variant with I/O holes is slightly shorter. The Raspberry Pi Zero has a third top for boards that don't have any I/O pins attached.
There are cases for the:
The models are designed in OpenSCAD; the source files are at https://codeberg.org/asciipip/slim-raspberry-pi-case.
The author marked this model as their own original creation.