... and close the gas valve 3,Alarm,security HOT!lpg gas detector with shut off valve Features:Adopts ... control system (burglar alarms, building talkback system and tri-meters reading transmission). High stability, long working lifeWall mount, elegant ... renew automatically.Parameters: Gas detectedcoal gas ,natural gas ,LPG(liquefied petroleum gas)SensorNew Nanotechnology sensor, super long working ...