"Flying fish" mechanical calculator buttons
MCbx 2020

Printing information:
Prusa Mk3, 0.1mm, 100%, no supports.
In my setup adding supports caused presence of a very hard to remove support in the slot into which the metal part goes.

Lots of round parts.

Post-processing: Polish its rough edges. If too high, remove material from the bottom. There's 8mm of hole, should be sufficient.

Important information:
Made in FreeCAD and had to export it this way (mesh generated with "meshing" workbench), as built-in STL exporter made defects in the round hole in the top of the mesh. The defect is less visible now.