Protect your family with the Kidde Firex Smoke Detector, Hardwired with Battery Backup, Smoke Alarm. The hardwired, ionization Kidde Firex Smoke Detector, Hardwired with Battery Backup, Smoke Alarm operates on a 120-Volt power source with a 9-volt alkaline battery backup. Using ionization sensor technology, the Kidde Firex Smoke Detector alerts to invisible fire particles, even during power outages. The Kidde Firex Smoke Detection provides a kit of hardwire adapters for quick & easy replacement of Firex & First Alert/BRK hardwired smoke alarms. The Kidde Firex Smoke Detector, Hardwired with Battery Backup has green, constant LED light that indicates AC power is connected. Red LED blinking lights flash for standby, if the alarm senses combustion, fire, or smoke, alarm memory if the alarm is activated, and hush mode. UL Certified with a 10-year limited warranty. Meets requirements of UL217, NFPA72, The State of California Fire Marshall, NFPA 101, FHA, & HUD.