... . Relay Module1. It can be wired to respond to smoke alarms, CO alarms, Heat alarm or both.2. Enables AC or DC powered ... .4. Fits in most junction boxes.5. Connects Firex smoke alarms with : Lights, Sirens, Exit signals, Exhaust fans, Other auxiliary devices ... , heat, smoke/CO, and CO alarm models: S598 series, H598 series, CPS598 series, C598 series. These are low-voltage interconnect alarms with a ...