First Alert 1046869 Interconnect Hardwire 2-in-1 Smoke & CO Alarm with Battery BackupThe SMICO100 AC Interconnect Hardwire 2 in 1 Smoke and CO Alarm with Battery Backup utilizes First Alert's Precision Detection technology and meets the latest industry standards. Easily install and interconnect multiple detectors together to create an alarm system throughout your home. First Alert's Precision Detection advanced sensing technology complies with the latest industry standards to reduce cooking nuisance alarms and provides early warning