The Bogen Nyquist NQ-S1810CT-T1 VoIP Ceiling Speaker offers increased flexibility where installers can use the VoIP speaker as a source for up to four (4) secondary passive 25V/70V speakers in a local speaker network, while retaining two-way intercom via the MEMS microphone on the VoIP speaker. The NQ-S1810CT-T1 can also serve as a PoE-based SIP endpoint in 3rd-party systems when operating in Standalone mode.