BRK 120V 10 Year White AC/DC Smoke Alarm Hardwired The SMI105-AC Interconnect Hardwire Smoke Alarm with 10-Year Battery Backup uses First Alert s Precision Detection advanced sensing technology and meets new industry standards. Interconnect multiple alarms together to help provide an early warning throughout your whole home and have peace of mind knowing the 10-year battery backup provides continuous protection in the event of a power outage.