The Kidde SM120X can be used to activate auxiliary warning devices such as external bells and sirens, hallway or stairway lighting. This relay will only activate when it receives a smoke signal from an interconnect Smoke Alarm. Activates or deactivates auxiliary devices such as bells, lights and ventilation systems For use with all interconnected installations that contain smoke alarms and smoke/CO combo units and heat detectors The power supply portion of this module can be used with manual pull stations, flow switches and spot type heat detectors