["An all-round SIP phone for clear communication. The SIP-T44U is a feature-rich business tool for premium communications and advanced functionality. This is a 12-line IP phone with a 2.8-inch black and white display and EXP43 support. With United Yealink Optima HD Voice technology and wideband codec, the T44U gives you excellent audio quality and crystal clear voice communication. Performing calling functions feels more responsive and faster. In addition, the T44U has two USB ports that allow Bluetooth, Wi-Fi, USB headsets and USB recording, and you can use any two of them according to your needs. Yealink's new T4U series features the same elegant design of the T4 line", "but with improvements for even better interoperability and collaboration. Only the BH76 headset supports the intelligent channel switching function"]