The Universal Security Instruments AMI1061SB 2-in-1 Sensing Plus Hardwired Smoke and Fire Alarm provides 10 years of continuous protection against deadly threats in the home. New Sensing Plus Multi-Criteria Detection provides the benefits of both photoelectric and ionization alarms in one 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. This 2-in-1 alarm includes a 10 year lithium free battery backup that will never have to be replaced throughout the life of the detector, giving you a decade's worth in peace of mind even in the event of a power outage.