You are Buying a brand New And Factory Sealed Kidde 10-Year Worry Free Smoke Carbon Monoxide Detector, Lithium Battery Powered with Photoelectric Sensor.... The photoelectric Kidde 10-Year Worry Free Smoke Carbon Monoxide Detector, Lithium Battery Powered, Fire Alarm operates on a 10-year, sealed, tamper-resistant, lithium battery. Using photoelectric electrochemical sensing technologies, the Kidde Smoke Detector alerts to visible fire particles, while the Kidde Carbon Monoxide Detector alerts of poisonous carbon monoxide gas, even during power outages. The Kidde 10-Year Worry Free Smoke Carbon Monoxide Detector, Lithium Battery Powered, Fire Alarm warns of fire, carbon monoxide, or low battery. Blinking LED light follows smoke alarm and sound pattern. Hush mode silences alarm for up to 10 minutes, while the LED light blinks every 10 seconds. A constant LED light will blink once every 10 minutes to indicate that power is connected. A low battery alarm will chirp every 60 seconds to indicate that its time to replace the smoke alarm. UL Certified with a 10-year limited warranty. Meets requirements of UL 2034, UL217, NFPA72, The State of California Fire Marshall, NFPA 101, FHA, HUD....