Why

I own a "NorthWind" (City Edition Freiburg). The Fixture "Ortlieb QL2.1" (I think?) is by design faulty and will break after time.
As you can see on the picture with the ruler it is due to the bolt, which will come out.

So I made a 3D model, removing the mechanical part.

Dimensions

You can orientate on the height of the object: it is 6cm. (please keep in mind, that depending on the material you have to calculate shrinking.)

Printing

I used PETG with an 80% infill and it is very strong. If you have experience with other materials in combination with this model, please leave a comment.

Attachments

You will find two Versions. I would suggest to use version 2, because it is stronger.
There is also an blender-file for both versions.
Feel free to do with it, whatever the GPL-License accepts^