-- Posted by jimb11 at 11:18 am on July 12, 2008 I have a Kyocera KX9D Oystr phone. I have tried a couple of hands free corded headsets but the answer/end button doesn't work. I plug in the 2.5 mm plug into the phone's jack and I can hear the phone ringing in the headset but when I push the answer/end button to answer the phone nothing happens. The phone keeps ringing and then goes to voice mail. Anyone know what could be wrong? Anyone know which headset would work with my phone and if so what retail stores sell it? -- Posted by bravosquadsas at 11:24 am on July 12, 2008 you need one that plugs into a port with more than just a jack slota a head phone jack port doesnt have the ability to transfer sound in, nor can they transmit electronic signals to answer or end the call. try buying one from the manufacturer, have a look at their website.