A horizontal version of the famous Monster Mouth headphone holder but changed to be made horizontal so it can pinch on desks that have vertical walls on the side (see images).
It accommodates desks up to 25.83mm thick by default and you can scale it. It is 90mm long (screw excluded).
Check the printing notes for details.
In my pictures, printed with supports facing me. I've since reprinted it because it failed. My current one was printed from bottom to top, that is to say that the "teeth" part was the first thing that printed.
This is the right orientation to print it because of the way tension is applied on the "arm" part. Otherwise, it means that that tension will be between layer lines instead of along it