Clamp style headphone holder to attach to ones desk. PLA or PETG is fine. I recommend 3 perimeters layers and 25% infill minimum. Also, a small piece of gasket applied to the top of the clamp will help keep the clamp in place when attached to a smooth surface. 

The screw will print with the head up. The tip of the screw rotates freely to mitigate the screw wanting to “walk” when pressure is applied. A small bit of support needs to be used inside the center cavity in the middle of the tip (see photo). Also, a brim should be used with the screw, especially when using the MK4 input shaper settings.