Grandstream HT813 Telephone Adapter Replacement Handsets so all that remains is

so all that remains is crystal-clear audio quality

With programmable keys

Premium Audio: 8-microphone array with noise reduction and 6 m voice pickup range for clear

and provides interface to legacy paging systems

life-like voice communications

Grandstream HT813 Telephone Adapter Replacement Handsets so all that remains isThe HT813 is an analog telephone adapter that offers backup lifeline support using a PSTN line. It is designed in an ultra compact size that features HD voice quality, advanced VoIP functionality, high end security protection, and multiple auto provisioning options. These advanced features also allow service providers to offer high quality IP service to customers looking to upgrade to VoIP.