The Combustible Gas Detector signals an alarm when dangerous flammable gasses are detected. This unit provides detection of Methane (natural gas), Propane, Ethane, Butane, Hydrogen, Ethylene, Ethanol, ISO-Butane, NOL, Gasoline, Acetylene, Methyl Ether, Ammonia, Hydrogen Sulfide, Industrial Solvents, Benzene, Alcohols, Acetone, Toluene, and Xylene. Features a sensitivity of 5ppm and a sensor life of 300 hours. Powered by four AA batteries. MSHA approved.