Universal Security Instruments SS-770 Battery-Operated Ionization Smoke and Fire Alarm, Model SS-770-24CC Ionization Smoke and Fire Alarm responds quickly to fast-flaming fires to protect your family against deadly threats in the home 9-volt battery (included) operates the alarm and continues protection in the event of a power outage Features an audible low battery indicator, a cover to protect against contaminants and an alarm/power test button to ensure that the device is functioning properly Fast and easy to install with all mounting hardware included and no wiring required Comes with a 3 year limited warranty