The Kidde i12010SCO is a hardwired combination smoke and carbon monoxide alarm that contains a 10-year, sealed battery backup. This alarm uses breakthrough technology to offer a fast response to real fires, including smoldering and fast-flaming, as well as protect you from carbon monoxide and dramatically reduce the chance of nuisance alarms. The Intelligent sensor technology combines the detection capabilities of an ionization smoke sensor – which is more likely to detect smaller, less visible fire particles, like those produced by flaming fires – with that of an electrochemical sensor, which is used to detect CO.