Attributes . Hush feature: Temporarily silences nuisance alarms; Red LED: Flashes every 30-40 S to indicate that the smoke alarm is receiving power; Test button: Tests unit?s electronic circuitry, horn and battery function; Battery operated (9V battery included): Protects even during power outages; Tamper resist locking pin: Helps deter from theft or tampering; Low battery indicator: Smoke alarm will chirp in the event of a low battery; Twist-off mounting: For fast installation and easy, safe battery replacement; 10-YR . Names