Annunciator, Saturn V launch vehicle engine, SC-113

The launch vehicle engine annunciator is a display located on the Apollo command module's main display console (MDC). Part of the Caution and Warning Subsystem, which monitored critical parameters of most of the spacecraft operational systems, this display alerted the crewmembers to malfunctions of any of the launch vehicle engines or "out-of-tolerance" conditions when they occurred in any of the engines.