Universal Security Instruments Battery-Operated Ionization Smoke and Fire Alarm, Model MI3050 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 Auto sensitivity calibration provides superior nuisance alarm protection and creates consistency in alarm sensitivity Fast and easy to install with no wiring required Comes with a 10 year limited warranty