These are a set of 5cm tall feet for the Fractal Ridge PC case. With two variants, one for VHB tape, and another for threaded inserts using the M2 screws for mounting SSDs provided in the case.
This will allow the Ridge to be used in both Horizontal or Inverted Horizontal orientations
They also feature a recess to allow the installation of some anti-slip foam, so the case doesn't move or slide.
Printed these un PLA (4 walls, 25% infill) without much trouble. For the long run maybe other filament would be a better fit, but it was what I had on hand.
The author marked this model as their own original creation.