The First Alert SA520B Wireless Interconnect Integrated Smoke Alarm links the alarms throughout your home. This 120V AC hardwired wireless detector with battery backup integrates single alarms into a system. By adding Wireless Interconnect battery powered alarms elsewhere, when one alarm sounds, all alarms will be notified. Easily link alarms with the press of a button. The RF Interconnect technology continues to provide a reliable and secure radio frequency communication between Wireless Interconnect alarms. This technology features 915 MHz frequency with 65,000 security codes, and three (3) channel frequency hopping.
Easy access battery drawer: no need to remove an alarm from the ceiling to change battery.
Includes 10-year limited warranty. Meets UL standards.