Fanvil / Sennheiser Electronic Hook Switch (EHS) Adapter - Inc RJ9 Connector Cable Connect DECT base to Fanvil IP phone with EHS20 adaptor in order to achieve remote control and allow users to answer and end the calls by press the multi - function button on headset COMPATIBLE HANDSETS Fanvil X2/X2P IP Phone X3S/X3SP/X3G IP Phone X4/X4G IP Phone X5S IP Phone X6 IP Phone FEATURES Hear ring tones Answer calls End calls Mute the microphone COMPATIBLE HEADSETS Jabra only.