The SIP-T42U IP phone is a feature-rich business tool for excellent communication and enhanced functionality. This 12-line IP phone comes with numerous built-in programmable keys, ensuring improved productivity. With Yealink's Optima HD Voice technology and the Opus wideband codec, the T42U delivers outstanding audio quality and crystal-clear voice communication. The phone feels faster and more responsive when making calls. Additionally, the T42U has two USB ports that enable Bluetooth, Wi-Fi, USB headset, and USB recording, allowing you to use two of them as needed. The new T4U series from Yealink offers the same sleek appearance as the T4 series but with enhancements for greater interoperability and better collaboration.