Yealink SIP-T57w phone Explore more details about T57W: 1 - T57W: a premium phone for busy executives and managers with heavy call load 2 - T57W + EXP50: connect up to 3 EXP50 expansion units (detachable part and color screen) feature guides: 1 - high-definition screen: through compatibility with fully adjustable screen, the Yealink T5 business phones series easily meet viewing needs at various angles and under different lighting conditions, and also provide an improved user experience. 2 - Acoustic Shield technology: the Yealink T5 business phones series is designed with Yealink Acoustic Shield technology to deliver crystal-clear sound clarity for remote participants by using multiple microphones to create a virtual shield. 3 - Wireless phone: the Yealink New T5 business phones series supports DECT phone compatibility via the Yealink DD10K DECT dongle, up to 4 wireless phones. 4 - advanced wireless connectivity: built-in Bluetooth 4.2 for wireless headset connection and improved mobility. Wi-Fi 2.4G / 5G to help businesses maximize wireless network use, reduce internet cable costs, and support clean and tidy workspace connections.