Protect your family with the Kidde 10 Year Worry-Free Smoke Detector, Lithium Battery Powered, Fire Alarm. The Kidde 10 Year Worry-Free Smoke Detector, Lithium Battery Powered, Fire Alarm operates on a 10-year, sealed, tamper-resistant, lithium battery. Using ionization sensor technology, the 10 Year Worry-Free Smoke Detector, Lithium Battery Powered, Fire Alarm alerts to invisible fire particles, even during power outages. A green LED light indicates that smoke alarm is in operation, while red LEDs blink to indicate standby, smoke or fire, and hush mode. After 10 years of use, the Kidde 10 Year Worry-Free Smoke Detector, Lithium Battery Powered, Fire Alarm will chirp once every 40-45 seconds to indicate the alarm needs to be replaced. UL Certified with a 10-year limited warranty. Meets requirements of UL217, NFPA72, The State of California Fire Marshall, NFPA 101, FHA, & HUD.