This premium phone is for executives and professionals, who expect high phone performance and a superior experience. With its 7-inch, 800 x 480-pixel backlit touchscreen and a modern interface, the T48S offers users simple one-click access, while lowing the learning curve thanks to its familiar and friendly user interface. The SIP-T48S is also with Yealink's Optima HD Voice technology and SILK speech codec for unparalleled audio clarity. Phone users will think they are sitting in the same room with one another. The T48S provides added flexibility for executives and professionals with its USB Bluetooth connectivity and its ability to switch calls to mobile phones.