Essential users are easy to recognize they are always on the phone. This power user relies on real-time voice communication and makes use of many advanced phone applications. The 9640 provides one-button access to advanced features such as Extension to Cellular and Extend Call to Mobile. These phones enable easy directory searches supported by contextual navigational menus and prompts. The 9640G adds integrated support for Gigabit Ethernet with an efficient PoE Class 2 rating.