1. 4 signal inputs (70V/100V audio signal) and 4 signal outputs (70V/100V audio signal) 2. Automatic detection of lightning strike to the audio line if it happens and the inputs and outputs will be cut off automatically 3. Four independent channels provide protection for up to 20A of audio power per channel 4. Protection against lightning strikes, over-voltage, and electric leakage. 5. Indicators for normal and protection state 6. Lightning protection grade: IEC529/EN60 529 protection grade satisfied: IP 20 7. Power activation by shorted signal 8. System ID setting using decimal system 8. Remote control function with remote controller