Kidde Nighthawk Carbon Monoxide/Explosive Gas Alarm ↓ Jump to Review BEST BANG FOR THE BUCK: Kidde Battery-Operated Carbon Monoxide Detector ↓ Jump to Review BEST PLUG-IN: First Alert CO600 ...

First Alert, America’s most trusted fire safety brand*, is partnering with America’s volunteer first responders to sound the alarm on the importance of updated smoke alarm standards.

While it is in the sleep mode it fails to alert users to new presences of either natural gas or carbon monoxide. The alarms have model number DD622NCV which can be found on the top of the alarm.