Louroe Audio Monitoring OS-1 3 kHz oscillator mounted on a PC Board and used when zone alarm is desired from a source other than audio. Used in conjunction with door contacts, motion detectors, and push-to-call buttons. Phantom powered from the Louroe Base Station, an instantaneous non-latching dry contact is required for activation. PC Board contains terminal block for connection to base station and lead wires for connection to momentary switch.