Atwood 31014 RV Propane Gas Detector - 12V DC, Black Alerts you to potentially dangerous levels of gas in your RV Fuel-cell sensor is less sensitive to false alarm triggers than other detectors Test/Mute button lets you test and silence alarm Four indicator lights: Green blinking (normal operation), Red flashing (active alarm), Red blinking (low power), Yellow blink (maintenance required) ETL tested and CSA certified