• Photoelectric sensor technology senses visible fire particles, associated with smoldering fires
• Operates on a 10-year lithium battery, eliminating the need for battery replacement, while providing reliable detection during a power failure
• End of life chirp notifies you when the alarm needs to be replaced
• Test-Hush button makes it easy to test the smoke detector and silence false alarms that occur from cooking or shower steam
• UL listed with a 10-Year limited manufacturer warranty on the alarm only (not a battery performance claim). Warranty begins when the alarm is powered on. If that date is unknown, it should be assumed that replacement is needed.