The line buttons on each model are fully programmable. You can set up line buttons to support either SIP registrations, or call features, such as speed dialing. You can also boost productivity by handling multiple calls for each SIP registration, using the multiple-calls-per-line appearance feature. Tricolor LEDs on the line buttons support the calling features and make the phone simple to use. Fixed function buttons on the 6800 series phones give you one-touch access to service, messaging, directory, hold/resume, transfer, and conference features. A full-duplex speakerphone lets you set up clear multiparty conferences for flexible, productive collaboration. The 6800 series provides exceptional noise isolation when used with a Cisco 500 Series Headset. The Cisco IP Phone 6800 Series maintains the same usability standards and standards for a context-sensitive user experience as the Cisco IP Phone 7800 Series. The 6821 IP phone has a 2.5-inch (240x120-pixel) grayscale display with white backlighting for easy reading. The 6861 has a 3.2-inch (320x120-pixel) LCD. The 6841 and 6851 IP phones each have a high-resolution 3.5-inch (396x162-pixel) grayscale display with white backlighting. The 6871 IP phone has a high-resolution 3.5-inch (480x272-pixel) color LCD. Localized language support is available for global users. See Table 6 for a list of available languages. The 6800 Series is also energy-efficient and eco-friendly, to support green initiatives. The 6821 and 6851 support Power over Ethernet (PoE) Class 2. The 6871 supports Power over Ethernet (PoE) Class 3. The 6821, 6841, 6851, 6861 and 6871 are Energy Star certified. The 6841, 6851, 6861 and 6871 support a power-save option that reduces power consumption during off-hours, saving costs by increasing energy efficiency. The 6861 phone is Wi-Fi enabled phone in 6800 series. It supports built-in dual band Wi-Fi up to 802.11n. Also provides reliable wireless connection and convenient connection to access point via WPS (Wi-Fi Protected Setup). The 6800 Series is ideal for businesses that want to update their phone systems from traditional analog or digital-based systems to an IP communications system with supported multiplatform call control systems.