... 2,In the house and close the gas valve 3,Alarm,security HOT!Home use gas detector with shut off valve Features: ... false alarm.Network signal: NO, NC and LEVEL can use the network signal to start up the fans.Fit for ... alarm situation eliminate, renew automatically.Parameters: Gas detectedcoal gas ,natural gas ,LPG(liquefied petroleum gas)SensorNew Nanotechnology sensor, super long working lifeAlarm ...