I have designed a simple wall bracket for the FritzBox 6591, which should also fit the 6590 and 6690 models.

Since I already had the drill holes of another model in the wall, the new holder should fit these. As a small experiment, the idea was to design a holder from one piece, which would result in some support for the two front supports, but this would not be a problem as the support points are on the inside. A cross-connection with a "dovetail" or similar would certainly have been an option, but I liked the idea of making a holder from one "cast" better.

A quick note:
The front of the supports are smoothed at the end. If you don't need this, simply deselect it in the slicer or check or adjust the settings for your filament.

I fastened the holder with two 4x35mm universal screws - half-round head (6mm drill holes with dowels were already present). After mounting the holder, place the box on the front supports and slide it horizontally against the wall, then let the box slide down into the holder - done.

Printed with Sunlu PLA+ white