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  • FirstAlert RM4 Wired-In Relay, 120V

FirstAlert RM4 Wired-In Relay, 120V


Usually ships in 3-5 days.


WARNING: Cancer and Reproductive Harm –


Use With BRK & First Alert Alarms

The 120VAC Smart Relay activates an auxiliary device when an alarm is triggered. The relay is designed for use with BRK and First Alert Smoke, Heat and Carbon Monoxide Alarms. When any interconnected alarm sounds, the relay contacts activate. The contacts automatically deactivate a few seconds after the alarm silences.

  • Activates auxiliary devices from smoke, CO and/or heat alarm signal
  • Works with all First Alert and BRK "Smart Interconnect" CO Alarms
  • Fits in most standard electrical boxes

When connected to BRK or First Alert alarms, the relay can activate an alert or other auxiliary device like a bell, siren, strobe light, exhaust fan, door closer, etc. The relay may be wired next to an AC alarm or from a remote location. This relay must be installed in a junction box.

FirstAlert: A Leader In Saving Lives

You can install FirstAlert products with confidence! Our products are designed to save lives. It's a responsibility we don't take lightly. We build each smoke alarm, carbon monoxide alarm, heat alarm, and fire extinguisher to the highest standards. Over the years, we've seen competitors come and go. We're still here, still making the most recognized consumer brands of smoke and CO alarms on the market.


  • Manufacturer Part #: RM4
  • Dimensions: 3.5 (L) x 1.5 (H) inches
  • Weight: 2.2 ounces
  • Operating Voltage: 120V AC 60Hz
  • Operating Current: .02 amps (standby/alarm)
  • Temperature Range: 40 to 100° F (4 to 38° C)
  • Humidity Range: 10 to 90 percent relative humidity (RH)
  • Interconnections: Up to 18 units of First Alert or BRK Smoke, CO and Heat Alarms. Maximum of 12 smoke alarms. See user's manual for details.
  • Listing: Meets UL217, UL2034, UL539, ULC S-531, CSA6.19 and ULCS-530 for accessories.