The AT&T GL2101-51 5-Handsets DECT 6.0 Cordless Phone with Call Blocker and Caller ID/Call Waiting lets you block unwanted calls while showing you who's calling. Talk and listen at the same time with natural, two-way conversations on both the handset and base with full-duplex handset speakerphones. The 2-inch white display features high-contrast text, making it easy to read caller ID and call history. The orange backlit keypad on the handset helps you dial numbers evenly, eving in low-light conditions. Stay connected longer. Enjoy up to 10 hours of talk time or up to 5 days of standby on a single charge, so your phone is always ready. ECO mode manages power consumption so the system uses less energy and you get the best battery life. Expand your phone system by adding up to 5 handsets using the GL210-0 accessory handset (sold separately), all with just one phone jack. Perfect for households that need flexible, room-to-room communication and a setup that fits your lifestyle.