The Broadcast Tools® Silence Sentinel® RJ is designed to monitor any two stereo analog audio sources for silence or an out of phase condition (polarity), generate alarms, and transparently switch to a back-up source using mechanically latching relays. Additional features include front panel controls, remote control inputs and status relay outputs, RJ45 audio connectors, plug-in euroblock screw terminals for remote control, dip switch configuration of silence detection from -20, -25, -30 and -35db below zero reference, precise alarm timing delay from off to 85 minutes, precise restore timing delay from off to 21 minutes. The Silence Sentinel® RJ may be set on a desktop, mounted on a wall or optional RA-1 rack shelf for mounting up to two units in 1-RU.