Keep your family safer with this hardwired smoke and carbon monoxide alarm; The 10 year battery backup means constant monitoring for the life of the alarm even if there's a power failureFeatures an electrochemical Carbon Monoxide sensing technology as well as intelligent smoke sensing technology to reduce nuisance alarms; Keyhole slots in the mounting bracket eliminate the need to remove the electrical box screws for installationIndicator lights on the face of the unit display the presence of smoke or carbon monoxide, while an 85 decibel siren provides a clear, loud warning upon detectionSimple to use, with a single test/silence button; Included 10 year lithium battery features a locked drawer to prevent tampering10-year limited warranty; Equipped with end-of-life signal chirp, so you know when it’s time to replace the unit for safetyRigorously tested to meet UL standards, Emits T3 patternFaster turnarounds on job sites with the easy-to-install, most-trusted alarms in home safetyFirst Alert has been the most trusted brand in home safety since launching the first residential smoke alarm in 1958 (Based on a First Alert Brand Trust Survey in February 2018)