Screw adapter
From 3.5 mm with M5 thread to 6.3 mm Suitable for Beyerdynamic DT-880 Edition/ DT-990 Edition and DT-770 Pro/ DT-990 Pro handset from summer 2019 (these have an M5 thread on the 3.5 mm jack plug)
beyerdynamic Headphone Adapter Screw M5