BRK, Battery Operated, Familygard Smoke Detector, Delivers Reliable Detection With A Built In Dual Chamber Ionization Smoke Sensor, Wide Openings Provide Plenty Of Air Flow For Quick Detection If The Smoke Alarm Identifies A Dangerous Condition It Will Trigger An 85 Decibel Siren, Location Flexibility Easy Installation, Uses A 9V Battery, Included, NOTE Please Check Your Local Building Code Requirements Before Installing This Product To Determine Compliance With Applicable Standards