The Ikea HEMNES desk is designed to be placed against the wall and thus has some unsightly holes on the back. This model plugs the holes so the desk can be used freestanding without looking too ugly.
The diameter is 35mm and 18.5mm height, it should fit in snug without having to force it, but maybe print just one first if you want to test it. If the black fastener from the desk is straight, the plug should be practically flush with the back surface. The design has a little sunken slat so you can pull it out if you want, it's hardly visible at a distance.
I haven't tested it but I guess it might work with other Ikea hardware with similar holes.
Used the default MK4 0.2mm Speed IS profile
Takes ~30 minutes and ~13.5g for 4 pieces
Finished by spray painting it matte white.
The author marked this model as their own original creation.