... 3,Alarm,securi High quality!Natural gas leak detector with shut-off valve Features:Adopts nanotechnology sensor with self-design ... alarms, building talkback system and tri-meters reading transmission). High stability, long working lifeWall mount, elegant appearance, low power ... gas ,natural gas ,LPG(liquefied petroleum gas)SensorNew Nanotechnology sensor, super long working lifeAlarm rangegas: 0.1~0.5%; ...