Smoke Detector,Andyssey Fire Alarm Smoke Detector 9V Battery Replaceable Photoelectric Smoke Alarms with Low Battery Warning, Fire Detector for Homes,with UL Listed, 4 Packs

【Battery Powered】Smoke detector replaceable disposable 9-volt carbon battery,replace the battery annually. Fire alarms smoke detectors in the battery power will be low when the “squeak” warning, accompanied by a red LED flashing.
【Operate Simply】The Smoke detector contains a test button. You can use this button to test whether the detector is normal to confirm the working status of the detector.
【Sound & LED Warning】 In case of an emergency,the smoke alarm can detect combustion particles in the air，an alarm tone of over 85 dB will sound throughout your entire home and the red LED will flash rapidly.