The Yealink T4 series is intended for discerning users with very high expectations of IP phones. It has been designed specifically for people who take great satisfaction in experiencing excellence actually being delivered. Revolutionary in appearance and advanced technical design, the T4 series is not only pleasurable and practical to use but also offers extra-large display screens that make pen and paper redundant in the busy office environment. In fact, the T4 series represents the cutting-edge of contemporary VoIP technology in action. Advanced features include support for gigabit networks, plus USB Bluetooth support for easy Bluetooth earphone use. Enhanced sound quality is delivered by the Optima HD Voice system which meets TIA 920 certification standards. In the T4 series, Yealink has set out to achieve the ideal marriage of perfection with performance.