... methane liquefied flammable gas for Ardu Product DescriptionMQ-2 gas sensor using gas-sensitive materials with lower conductivity in clean air ... the gas concentration using a simple circuit.MQ-2 gas sensor for liquefied petroleum gas, propane, high sensitivity of hydrogen, ... natural gas, city gas, smoke better sensitivity.6, there are four screw holes for easy positioning;Product Dimensions: 36 (L) * ...