Summary: They are the "substitute that Panasonic has come up with - I had gotten them before and they do not work as well with my phone as the TCA92's, which are discontinued but why I placed the order... I thought they were the old, discontinued inventory.
Summary: I HAVE TRIED SEVERAL DIFFERENT BRANDS OF CORDED HEADSETS AND HAD A VARIETY OF DIFFICULTY WITH THEM UNTIL I RECEIVED THIS PANASONIC HEADSET ABOUT A YEAR AGO AS A GIFT. IT IS WITHOUT DOUBT THE BEST EVER. MUTE AND VOLUME INCLUDED IN LINE AND THE RECEPTION IS JUST PERFECT.