Denon AH-GC20 - Manual (Page 25)

Information
Airplane use
Use the supplied audio cable and conversion plug for aircraft use in order
to listen to the on-board audio services on an aircraft.
NOTE
0 The supplied conversion plug may not be usable depending on the type of aircraft.
0 Do not use these headphones when the use of electric devices on the aircraft is
prohibited, or when the use of personal headphones to listen to on-board music
services is prohibited.
Storage in the carrying case
Remove the cable and plug from the headphones, fold and insert them
into the case.
NOTE
Do not force them into the carrying case. Doing so may damage the headphones.
Contents Preparation Connections Operation Troubleshooting Appendix
25