The First Alert GCO1 is a combination plug-in detector that monitors your home for dangerous levels of explosive gas (propane and natural/methane gas) as well as carbon monoxide (CO) simultaneously. It plugs into any standard AC wall outlet without blocking adjacent outlets, and includes a cord for flexible placement on a wall or surface away from the outlet.

When a threat is detected, the alarm sounds at 85 decibels to alert occupants quickly. A backlit digital display shows current and peak CO levels, making it easy to identify patterns from appliances, generators, or other sources. A 9-volt battery backup ensures continued protection during power outages.

The electrochemical CO sensor provides accurate carbon monoxide detection, while the semiconductor gas sensor detects propane and natural gas leaks. A single test/silence button allows easy alarm testing and silencing of nuisance alerts. No additional mounting hardware is required for installation.