A headphone holder with a screw for tightening it to the desk. Should work on desks up to about 35mm. 

There is a version with and without a hook. The main purpose was a place to store a seperate microphone and help with cables.

Hooked version needs supports on buildplate. Holder has some threads which may need supports, but printed fine without for me after the first few rotations. 

Print in pictures was printed with 0.15mm layer height using PETG.