... . 2.Our company specializes in producing colorimetric gas detection tube. All kinds of tubes have been granted the certificate ... countries. Carbon Monoxide, Carbon Dioxide, Oxygen, Wind direction(Smoking generating tube), Ammonia, Hydrogen Sulfide, Nitrogen Dioxide, Sulfur Dioxide, Chlorine, Benzene, ... ,NH3,PH3,SO2,C4H10,CH3Br,C2H3CL, CL2, HCN,HCL,HF,NO,NO2.And we also make tubes according to customer ...