This is a basic 1RU mount (44mm high) used for mounting a small network switch underneath an Ikea IVAR shelf. There are two different versions of the bracket - one screws directly into the shelf, one is larger and clips around the edge of the shelf.

I have used one of each so that the switch hangs on one end just hanging over the shelf, the other end screws in to the shelf to hold it all in place.

This requires 4xM6 thermal inserts that are 9mm (or less) deep, as well as matching screws.

Printed in PETG to hopefully not fall apart, so far it's going strong.