The CyberData Multicast Speaker is an economical Power-over-Ethernet (PoE 802.3af) and Voice-over-IP (VoIP) public address product. It easily connects to your PoE network with a single Ethernet cable connection. The speaker is capable of playing audio from any multicast source like the CyberData SIP Paging Server with Bell Scheduler (PN#011146). The CyberData Multicast Speakers small footprint and low height allows the speaker to be discreetly mounted in your ceilings.