Buy at Amazon.com Buy at Wayfair.com Detects CO, propane, and natural gas leaks Loud alarm Backlit digital display is easy to read First Alert has a range of reliable alarms, and the Explosive Gas ...

Carbon monoxide (CO) is a gas that has no color, odor or taste. Breathing it in reduces your bloodstream's oxygen levels. Because of these facts, it is frequently called the "silent killer.

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.

After alerting consumers to the presence of natural gas or carbon monoxide, the recalled detector can go into sleep mode when the alert lasts less than four minutes, according to the CPSC.