The First Alert SMCO210 10-Year Sealed Battery Combination Smoke & 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. NOTE: Please Check Your Local Building Code Requirements Before Installing This Product To Determine Compliance With Applicable Standards.