A well-equipped SIP phone for clear communication The SIP-T42U IP phone is a feature-rich business tool for excellent communication and advanced functionality. This 12-line IP phone has numerous integrated programmable keys, guaranteeing improved productivity. United YealinkOptima HD Voice technology and Opus wideband codec, the T42U offers excellent audio quality and crystal clear voice communication. The phone feels faster and more responsive when making calls. In addition, the T42U offers two USB ports in one phone, which Bluetooth, Wi-Fi, USB headset and USB recording. and you can freely use two of these ports as needed. Yealink's new T4U series offers the same elegant appearance as the T4 series, but with improvements for more Interoperability and better collaboration