Relay Module, Features Used to Activate Auxiliary Warning Devices Such As External Bells and Sirens, Hallway or Stairway Lighting, Will Only Activate When It Receives A Smoke Signal From An Interconnect Smoke Alarm, Includes (1) Set of Form C Contacts, Power Source Hardwired, Product Type Smoke Alarm Relay Module, For Use With Kidde Smoke Alarms, Manufacturer Warranty Length 1 yr, Maximum Operating Temperature 100 Degrees F, Minimum Operating Temperature 40 Degrees F, Operating Frequency 60 Hz