First Alert 2-pack 10YR Smoke & Battery CO *Power Type: Battery-Powered *Sensor Type: Electrochemical *Product Type: Smoke and Carbon Monoxide Combination Pack *Batteries Included: Yes *UL Listed: Yes *Battery Size: AA *Number in Package: 2 pk *Packaging Type: Clamshell *Test and or Reset Button: Yes *Low Battery Indicator: Yes *Color: White