The SMICO100-AC Interconnect Hardwire 2-in-1 Smoke CO Alarm with Battery Backup utilizes First Alert's Precision Detection technology and meets new industry standards. Easily install and interconnect multiple alarms together to create an alarm system throughout your home. First Alerts Precision Detection advanced sensing technology complies with new industry standards to reduce cooking nuisance alarms and provides early warning in the event of a home fire emergency Through early warning interconnect, when one alarm sounds, all compatible Quick Connect Plug allows for easy installation with no need to rewire Battery backup provides continuous protection during power outages Test/silence button for efficient testing to ensure alarm is working properly