Calibration Gas, CGA Number Not Applicable, Container Type Cylinder, Cylinder Capacity 105 L, Cylinder Diameter 3.2 in, Cylinder Height 12.8 in, For Use With All OEM Gas Detectors, Gas Mixture Hydrogen 400 ppm, Gas Type Methane, Nitrogen, Oxygen, Product Type Calibration Gas, Chemical Formula H2, CAS Number 1333-74-0, Accuracy +/-2 Percent, Background Gas Air, Calibration Certificate NIST, Cylinder Material Aluminum Alloy, Outlet Connection Size 5/8 In.-18, Outlet Connection Type UNF