I designed these mounts to fit the Keyhole mounting system that is usually found behind multiplugs or small systems that can be installed on the wall.
This particular design is meant to be used with IKEA's galant desks; the mount fits in the space between the table and the metal support bars.

The dimensions of the pin that will fit into the keyhole mounting system are:
d_head=7.40 mm
d_body=3.10 mm

In the .stl file the orientation of the object is right.
It should be printed with supports enabled to allow the pin to be printed.

Along with the .stl files, I also provide the .f3d file so that you can modify the support to your liking and adapt it to different keyhole mounting systems.

I was inspired in the creation of that design by this project