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