3-in-1 Gas Alarm Plug-In with 9 V Battery Back-Up

Gas alarm detects carbon monoxide (CO), propane, and natural gas. Digital display of the highest CO concentration measured since last reset. Verifies whether or not CO was detected whil you were away. Test and reset button included. Plugs into electrical outlet. 9 V battery backup included for continued protection in case of power outage.

*A carbon monoxide detector is required if you have a wood-burning or gas fireplace, furnace, water heater, gas stove, or garage adjoined to house.