The SIP-T58W is a user-friendly business phone. For optimal HD audio and video, Optimum HD audio, Yealink Noise Proof Technology, integrated Bluetooth 4.2 and dual-band Wi-Fi 2.4 G/5 G, media and storage applications up to 16 SIP accounts, Audio conference with up to 10 participants, Dual-port Gigabit Ethernet, PoE support, Supports up to 3 expansion modules EXP50, Supports Yealink/Unify Square Device Management Platform Note: Power supply available separately