... 2.Our company specializes in producing colorimetric gas detection tube. All kinds of tubes have been granted the certificate ... . Carbon Monoxide, Carbon Dioxide, Oxygen, Wind direction(Smoking generating tube), Ammonia, Hydrogen Sulfide, Nitrogen Dioxide, Sulfur Dioxide, Chlorine, Benzene ... etc. They can meet requirement of different customers.4.Tube Type: CO,CO2,H2O,H2S,NH3,PH3,SO2,C4H10,CH3Br, ...