Cisco Unified IP VoIP Phone 7911G - (Requires Call Manager) Graphical monochrome display with resolution of 192 x 64 pixels provides a scrollable 3-line intuitive access to calling features and text-based XML applications Hold button lights when pressed to put a call on hold and stays lit until the held call has been resumed Comfort-noise generation and voice-activity-detection (VAD) programming on a system basis IEEE 802.3af Power over Ethernet and from any Cisco Inline Power-capable switch Power Supply not included. Designed to work with Cisco Unified Communications Manager.