First Alert 1039741 Battery Electrochemical Carbon Monoxide Alarm 2 Pack New
First Alert 1039741 Battery Electrochemical Carbon Monoxide Alarm, Features an advanced electrochemical carbon monoxide sensor that accurately detects carbon monoxide levels, no matter where the detector is placed in the room.The alarm sequence should last 5-6 seconds. If it does not alarm, make sure fresh batteries are correctly installed, and test it again. If the unit still does not alarm, replace it immediately