... MQ-2 LPG I-butane Propane Methane Alcohol Hydrogen Smoke Gas Sensor Module Long Size: 32mm x width 22mm X height ... for home or factory gas leak monitoring device, suitable for liquefied petroleum gas, butane, propane, methane, alcohol, hydrogen gas, smoke and other ... competition, product development, graduation design New MQ-2 smoke gas sensor module liquefied natural gas modules smoke module