This is the PoE only Polycom IP 550 (NO AC Power Supply).  Polycom SoundPoint IP 550 desktop phone features Polycom’s revolutionary HD Voice technology, which brings life-like richness and clarity to every call.1,5 Polycom HD Voice technology incorporates wideband audio for over twice the voice clarity; Polycom’s patented Acoustic Clarity Technology for crystal-clear, noise- and echo-free sound, plus best-in-class system design for high-fidelity, faithful voice reproduction. Comprehensive, Cutting-Edge Feature Set. The SoundPoint IP 550 desktop phone delivers advanced features and capabilities, such as shared call/ bridged line appearance, busy lamp field (BLF), presence, text messaging, and buddy lists. The Polycom IP 550 phone also boasts an integrated XHTML micro-browser that allows users to take advantage of productivity-enhancing Web-based applications. Add the support of four lines, a backlit, highresolution, easy-to-read graphical display and flexible customizations options, and it becomes clear why the SoundPoint IP 550 is certain to meet the voice communication needs of the most demanding managers and professionals.

Key Features:

• Four lines
• No External Power Supply (PoE only)
• Polycom HD Voice technology, including support of G.722 wideband codec, Acoustic Clarity Technology 2, and systems design optimized for Polycom HD Voice technology
• Advanced functionality, including shared lines, busy lamp field, presence, and XHTML application
• Backlit 320 x 160-pixel grayscale graphical LCD
• Integrated IEEE 802.3af Power over Ethernet (PoE) support
• Dedicated RJ-9 headset port for Plantronics or GN headsets

For more details see Polycom IP 550 datasheet as well as Polycom IP Phone Reference Guide