Beyerdynamic Screwable Headphone Adapter M8The Beyerdynamic Screwable Headphone Adapter M8 suits headphones with M8 thread. The jack adapter with M8 thread can also be used for headphones with M5 thread, but only as a plug adapter. Key Features: Fits: DJX 1 DT 250 DT 290 DT 291 DT 294 DT 297 DT 331 DT 431 DT 440 DT 440 Edition DT 531 DT 660 DT 660 Edition DT 770 DT 770 old DT 770 Edition DT 770 M DT 770 PRO DT 770 PRO HT DT 831 DT860 DT 860 Edition DT 880 DT 880 old DT 880 Edition DT 931 DT