Universal Security Instruments SS-2895 Hard Wired Photoelectric Smoke and Fire Alarm Photoelectric Smoke and Fire Alarm responds quickly to slow-smoldering 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 5 year limited warranty