Calibration Gas, CGA Number Not Applicable, Container Type Cylinder, Cylinder Capacity 103 L, Cylinder Diameter 3.3 in, Cylinder Height 13.6 in, For Use With All OEM Gas Detectors, Gas Mixture Hydrogen (50 Percent LEL) 2 Percent, Oxygen 18 Percent, Gas Type Hydrogen, Oxygen, Product Type Calibration Gas, Chemical Formula H2, O2, CAS Number 1333-74-0, 7782-44-7, Accuracy +/-5 Percent, Background Gas Nitrogen, Calibration Certificate NIST, Cylinder Material Steel, Outlet Connection Size 5/8 In.-18