The Polycom SoundPoint IP 501* is a three-line Voice over IP telephone that seamlessly integrates with IP PBX and Softswitch vendors' IP solutions. As protocols develop and standards evolve, it's easy to update the phone in the field via a software download, thus enabling new features and functionality for the phone and protecting your investment. Whether you deploy MGCP or SIP standards, Polycom offers a solution that fits all your business communication needs. ` SoundPoint IP 501 MGCP 3-line IP desktop phone. Compatible Partner platforms: Sphere. Suitable for country groups: 1, 2, 3, 6, 7, 48, 71, excluding Korea and Russia. Ships with: IEEE PoE cable. No AC adapter included.