High efficiency, more than 85% Class D amplification. 6 Line input sources, including 2 Audio Streamers (Input 3, 4). USB ports for playing music files from USB Flash Drive (Input 3, 4). Each zone Stereo/Mono output selectable. Enable control over Ethernet TCP/IP. Support Control APP. PRE-AMP output on Zone16. Built-in IR receiver & IR remote controller for Source select/Volume/Treble/Bass. 12V DC trigger output to external device when the system is power on. 12V DC mute trigger input from the external devices. RJ45 Ethernet port for the wired connection to the local network. Another RJ45 Ethernet expansion port for connecting with smart TV or other device. RS-232 port allows 2-way communication with the Home Automation system. Expandable up to 18 Zones by additional 2 units. 6 LEDs for 6 zones Power On, Standby and Mute. Built in IR emitter.