Robust interoperability - compatible with a broad array of SIP call platforms to maximize voice quality and feature availability, while simplifying management and administration;Flexible configuration options - provides multi-unit connectivity and expansion microphones, and integrates with Polycom HDX, to meet the needs of many different types of rooms;Polycom HD Voice - software and hardware technology brings lifelike audio clarity, making your conference calls more efficient and productive - Built-in Power over Ethernet (PoE). An optional A/C power kit also available;Polycom Acoustic Clarity Technology - delivers the best conference phone experience, without compromises;Built-in 2.5mm applications port, which enables you to connect the conference phone to a mobile phone for productive calls even where no network connection is available (or to a computer for calls using PC-based soft phone clients)