When connecting my Beyerdynamic DT 900 Pro X headphones to the laptop, they stick out quite some distance because of the thread to screw on the 6.3 mm adapter. This spacer fills the gap which looks nicer and hopefully protects the plug from being bent accidentally.

Use a very fine layer height to print the fine detail of the M5×0.5mm ISO metric fine thread. I used a matching screw to remove excess filament, but it would probably work much better with a proper thread cutter.

Layer height 0.05mm, no supports.