The Silence Monitor III PLUS is designed to monitor any stereo or two independent monaural sources, generate alarms and transparently switch to back-up source equipment when silence is detected. Now with LEDs. 

Broadcast Tools Silence Monitor III Plus Features:
•Transparent stereo or dual monaural program switcher with front panel switcher transfer switch and indicator LED.
•Dipswitch selection of silence detection of -23, -25, -35 and -45db
•Precise time delay from 2 seconds to 85 minutes
•Precise restore timing delay from off to 42 minutes
May be configured for stereo or dual independent monaural operation
•Active balanced inputs
•Front panel switcher transfer switch
•Front panel \"Mute\" switch with built-in sonalert and remote defeat input
•Front panel \"Manual/Automatic\" switch with front panel LED, remote input and relay
•Front Panel Alarm \"Reset\" switch, Tripped LED and relay
•External (\"Ext\") alarm input with front panel indicator and relay
•Front Panel Power LED
•Two independent audio alarm relays
•Two pulse open collector alarm outputs
•Auxiliary SPDT relay with user configuration of pulse and
•Plug-in euroblock screw terminals

The SM III Plus may be set on a desktop, mounted on a wall or optional RA-1 rack shelf for mounting up to three units in 1-RU.