Calibration Gas, CGA Number CGA 600, Container Type Cylinder, Cylinder Capacity 34 L, Cylinder Diameter 2.9 in, Cylinder Height 10.75 in, For Use With All OEM Gas Detectors, Gas Mixture Carbon Monoxide 50 ppm, Methane (50 Percent LEL) 2.5 Percent, Oxygen 19 Percent, Gas Type Carbon Monoxide, Methane, Oxygen, Product Type Calibration Gas, Chemical Formula CH4, CO, O2, CAS Number 630-08-0, 74-82-8, 7782-44-7, Accuracy +/-5 Percent, Background Gas Nitrogen, Calibration Certificate NIST