The Universal Security Instruments MI3050SB-6P 2-in-1 Smoke and Fire Smart Alarm provides 10-years of continuous protection against deadly threats in the home. New patented Universal Smoke Sensing Technology provides the benefits of both photoelectric and ionization alarms in 1 device to protect against fast flaming and slow smoldering fires. Perfect for new or replacement installations, this maintenance-free alarm is suitable for houses, apartments and mobile homes. The sealed battery included will never have to be replaced throughout the life of the alarm, giving you a decade’s worth in peace of mind even in the event of a power outage.Lithium-free alkaline permanent power from Duracell Duralock is safer and more eco friendlySuperior resistance to false alarms, no batteries to change, no battery chirpsQuick find alarm origination feature easily identifies originating alarm to sound in an interconnected system10-year product end of service life warning – sounds when it is time to replace detector10-year limited warrantyThis Alarm conforms to UL 217 standards, California State Fire Marshal approved nd Federal Housing Authority FHA approved to exceed industry standards