The Broadcast Tools Silence Sentinel Basic is a stereo silence sensor designed to monitor any stereo or two independent monaural sources and generate alarms when silence is detected. In keeping with its basic approach, it doesn't incorporate an audio switcher. 

The Silence Sentinel Basic may be set on a desktop, mounted on a wall or optional RA-1 rack shelf for mounting up to four units in 1-RU.

Broadcast Tools Silence Sentinel Basic Features:
• Front panel, remote control and relay monitoring
• Plug-in euroblock screw terminals
• Plug and Play (NO POTS) installation
• Dipswitch selection of the following: silence detection of -20, -25, -30 and 35dB below zero reference; precise time delay from OFF to 5 minutes in 2 or 20 second increments; restore delay timing of OFF, 5, 30 and 90 seconds
• Two SPDT alarm relays with LED indicators