Supports up to 3 additional expansion modules (sold separately). HD Voice technology provides 7kHz clarity on all audio paths. Acoustic Clarity technology suppresses background noises and delivers echo cancellation, so you can enjoy crisp, high-quality phone conversations. 12 lines offer increased flexibility. 3.5″ color LCD screen features TFT technology and has a 320 x 240 resolution for sharp visuals. Call waiting and caller ID let you see the name and number of incoming calls before you answer. 2 Gigabit Ethernet ports provide super-fast data transfer rates. 1 USB port offers added connectivity for media and storage applications. 3-way audio conferencing allows you to talk to multiple parties at the same time. Backed by the manufacturer’s 1-year limited warranty.