As much as I like the Joy-IT JDS2915 Signal Generator, what I didn't like was that it came with a metal case without rubber feet. The metal scratches on the desk, and due to its profile it also wasn't possible to attach rubber feet. So I just created a small frame to solve the problem.

Print the frame part twice. You can use almost any material, but I recommend PLA (with PETG I had a lot of stringing issues). You do not need to use supports, and avoid to use a brim if possible.

When the parts are printed, remove the four lower case screws. The frame parts are just put to the bottom edges and fixed with the original screws. After that, rubber feet can be attached to the frame parts.

The modification can easily be reverted, and the case stays closed all the time, so I assume that the warranty is not voided. However, you are doing this modification at your own risk.