The BESANTEK BSTMG09 Heavy Duty Multi-Gas Leak Detector for CH4/LEL, O2, H2S, and CO can be applied to underground coal mining, petrochemical industry, municipal, environmental protection and other spaces where multi gas may exist. The BST-MG09 can be used for detecting Methane (CH4) or Combustible Gas (LEL), Oxygen (O2), Carbon Monoxide (Co), and Hydrogen Sulfide (H2S) gases simultaneously. This model alarm users by light, sound, and vibration. This device is portable, anti-explosion and intrinsically safe.