T43U VoIP SIP telephone, 2 x Gigabit Ethernet, 12 x line keys, PoE required, AC optional, 3.7 inch backlit LCD, HD audio, RJ9 headset jack, EHS support for specific Jabra and specific Plantronics headsets (cable required, SKU #EHS40), 2 x USB, Wi-Fi support (requires adapter, SKU #WF40 or SKU #WF50), Bluetooth support, SKU #BT41, optional wall mount bracket, SKU #YKT4XWMB, add up to 2 expansion modules (sidecar / attendant console, SKU #EXP43), supports YDMP / YMCS. Optional AC power supply, SKU #PS5V1200US