All items are Brand New in Original Manufactures Packaging. Optima HD Audio Up to 12 SIP Accounts Integrated PoE with Dual-port Gigabit Ethernet (Router & Switch) 6 multi-functional line keys AC adapter (PS5V1200US) is NOT included. It has a faster, more responsive interface than the T42G and offers better overall performance. It is with Yealink Optima HD Voice Technology and wideband codec of Opus for superb sound quality and crystal clear communications.Plus, with an all-new USB port, the SIP-T42S boasts unparalleled functionality and expansibility with Bluetooth, Wi-Fi and USB recording features. The new T4S series offers the same elegant appearance of the T4 line, but with improvements for greater interoperability and collaboration. Yealink T4S series IP Phones. Integrating cutting-edge features like Wi-Fi and Bluetooth connectivity, the T4S series enriches business users daily collaboration. It also protects business users investment with its effortless deployment and broad interoperability with UC platforms and IP PBX systems. Optima HD Audio With Yealinks Optima HD audio technologies, industry-leading acoustic clarity and newly-added support for Opus to its broad audio codec list, the Yealink T4S guarantees a lifelike collaboration experience. By supporting Opus, Yealink T4S series delivers better audio quality in both high-bandwidth and poor network conditions, comparing to other wideband or narrowband codecs. The item "Yealink T42S-SIP PoE IP Phone (no AC adapter) Gigabit VoIP, Optima HD Audio" is in sale since Monday, January 01, 2018. This item is in the category "Computers/Tablets & Networking\Enterprise Networking, Servers\VoIP Business Phones/IP PBX". The seller is "mikethephoneguy" and is located in Charleston, South Carolina. This item can be shipped to United States.