The First Alert® SMICO110 10-Year Battery Smoke and Carbon Monoxide Alarm provides reliable 2-in-1 protection against both fire and carbon monoxide in an easy-to-install detector. Featuring superior safety features like a 1-touch test/silence button to confirm the combination alarm is functioning correctly and silence false alarms, the combination alarm features a built-in 10-year sealed battery that provides uninterrupted power for the life of the detector. No need to worry about the cost or hassle of battery replacements for a decade. An end-of-life warning lets you know when the alarm should be replaced.