Install the First Alert SM210 10 year sealed battery smoke alarm and CO400 battery-operated carbon monoxide alarm safety value pack for protection against fire and carbon monoxide (CO). The SM210 smoke alarm features First Alert’s precision detection advanced sensing technology and meets new industry standards. While the CO400 carbon monoxide alarm easily installs and provides reliable CO protection.First Alert’s 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 emergency10 year sealed battery eliminates battery replacements and low battery chirps for the life of the alarmSlim profile design is half the depth of a standard alarm