Marine UL Listed with red function light. Remains ON and monitoring even when Gas Control Panel is OFF. It sends an alarm signal to the Gas Control Panel when LP Gas is present at 10% Lower Explosion Limit (LEL) or more. Up to 2 additional detectors can be added to systems (1300-7760 & 1300-7761-KIT) with a 10ft. or 20ft. Quick Connect Cable (1300-7721-120 & 1300-7721-240 respectively). Each Detector draws 163 M.A.