This is a High Performance switcher for composite and balanced stereo audio signals.  Has high bandwidth 620Mhz-3dB, Automatic, front panel or contact closure, Automatic Standby Switching (On/Off)-when enabled, any interruption of the input 1 signal (default), automatically switches input 2 to the output, Level (Gain) and EQ (peaking) controls.  This unit was working when pulled from service.