Used in combination with the Yealink IP Conference Phone CP920/CP860, the CPN10 is a new product designed by Yealink, to add PSTN connectivity to IP based Conference Phones, the CP920/CP860. With this PSTN box CPN10, our Yealink CP860/CP920 can both support the conferencing call based on SIP protocol and PSTN. With one PSTN cable in your meeting room, you can easily connect the PSTN box CPN10 with Yealink professional conference phone CP860/CP920 and start up your local three-way conference. Meanwhile, plus CP860’s/CP920's HD audio quality, build-in 3 microphone array, full-duplex technology, acoustic echo cancelling technology as well as its rich call handling features, such as USB call recording, linkage to mobile phones or PCs, you can conveniently enjoy the conferencing call easily with excellent speech quality in your meeting room. • Support Yealink IP Conference Phone CP860/CP920 • Plug and play • Easy to use • No additional power needed • USB call recording • Support up to 2 cascaded CPN10 to setup PSTN conference