The First Alert SMCO210 10 year sealed battery combination smoke and carbon monoxide alarm with slim profile design uses First Alert’s precision detection advanced sensing technology and meets new industry standards. This 2-in-1 alarm provides convenient protection against both fire and carbon monoxide (CO). Also equipped with a 10 year sealed battery to eliminate the need for battery replacements and low battery chirps.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 emergencyProvides reliable 2-in-1 protection against both smoke and carbon monoxide in an easy to install alarm10 year sealed battery eliminates battery replacements and low battery chirps for the life of the alarmEnd-of-life warning lets you know when it’s time to replace the alarmSlim profile design is half the depth of a standard alarmTest/silence button for efficient testing to ensure alarm is working properly