... MQ-2 LPG I-butane Propane Methane Alcohol Hydrogen Smoke Gas Sensor Module Long Size: 32mm x width ... or factory gas leak monitoring device, suitable for liquefied petroleum gas, butane, propane, methane, alcohol, hydrogen gas, smoke and ... other monitoring means.Applicable occasion: SCM learning, electronic competition, product development, graduation design New MQ-2 smoke gas ...