AC *must* give two prong adapters on 77HD and 787
Both the 77HD and 787 use the three-prong system in J. IMHO that's a silly concept to start with BUT if they do this they have to give pax adapters to use their own headphones.
I know many of us travel with them but with the majority of new aircraft not using this system AC should go back to giving our these adapters, probably worth 2¢.
Please, AC, make this change ASAP. Very frustrating!