Nextiva Deskphones Compatible Headsets The below information was provided by Poly/Plantronics tech support on 9/23/22 (Updated from 4/27/2022) regarding Nextiva SIP X-815, X-835 & X-885 phones. For wireless headsets, you can use any Current Deskphone Compatible Headsets and Snom EHS wireless headset adapter. ***The Poly APP-51 EHS Cable in no longer considered a compatible solution which was originally recommended … Continued