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 photoelectric sensor technology, the 10 Year Worry-Free Smoke Detector, Lithium Battery Powered, Fire Alarm alerts to visible fire particles, even during power outages. An LED light follows the alarm sound pattern & blinks 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 2 times every 30 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.