Additional Details ------------------------------ Product description: Especially designed for busy executives and professionals, Yealink SIP-T57W is an easy-to-use Prime Business Phone with an adjustable 7-inch multi-point touch screen that you can not only easily and flexibly find the comfortable viewing angle according to the personal and environmental needs, but also get a rich visual presentation and easy navigation with just one-touch. With the built-in Bluetooth 4.2 and the built-in dual band 2.4G/5G Wi-Fi, the SIP-T57W IP Phone ensures you to keep up with the modern wireless technology and take the first chance in the future wireless age. Its built-in USB 2.0 port allows for USB recording or a direct wired/wireless USB headset or up to three Yealink EXP50 expansion modules connection. Benefitting from these features, the Yealink SIP-T57W is a powerful and expandable office phone that delivers optimum desktop efficient and productivity