Kidde 21009663 10-Year Worry Free Battery Operated Smoke Alarm This smoke alarm is ideal for the living Area Goodbye late night low battery chirps, an end-of-life signal tells you when it is time to replace the alarm Unit, end of Life signal chirps every 30-45 seconds when alarm needs replaced Alarm is UL listed and is equipped with a piezoelectric Horn that is rated at 85 decibels at 10 ft Alarm is equipped with test - Reset button, tests the circuitry and Horn and resets memory after alarm has sounded 10-year worry Free battery operated smoke alarm (3-pack) is powered by sealed, long-life lithium batteries for ten years