Calibration Gas Gas Name Carbon Monoxide Propane Oxygen Gas Mixture 50 PPM Carbon Monoxide 1.05 Percent Propane (50 Percent LEL) 18 Percent Oxygen Balance Nitrogen Background Gas Nitrogen Cylinder Capacity 103L Cylinder Material Steel For Use With Any and All OEM Gas Detectors Connection Size C-10 (5/8 in UNF) Max Pressure 1000 psi Cylinder Dia 3-21/64 In. Cylinder Height 13-2/3 In. Accuracy +/-5 Percent Calibration Certificate NIST