C-Clamp style headphone holder.

Before you glue the Plate to the top of the Screw, you must first thread on the Screw & Nut onto the Clamp Body. 

The C-clamp base, screw & nut are from my other design, so the top pieces are interchangeable.:

https://www.printables.com/model/507508-c-clamp-wyze-v2-camera-stand

Print supports are required.

Different mounting system.