The Proco Panic Button is designed to enable live entertainers on stage to switch their microphone signal from Output A (Front of House normal operation) to Output B (Backstage or alternate location) for emergency contact with road personnel or the Monitor mix engineer.
The Panic Button
Channel B can also act as a mute switch, although the road personnel can still monitor the mic signal. Phantom power from the FOH mixer powers both channels when condenser microphones are being used, and the channel switching is silent. If the battery in the Panic Button dies, the circuit automatically reverts to Channel A.