Calibration Gas Gas Name Carbon Monoxide Propane Oxygen Nitrogen Gas Mixture 50 PPM Carbon Monoxide 1.05 Percent Propane (50 Percent LEL) 18 Percent Oxygen Balance Nitrogen Background Gas Nitrogen Cylinder Capacity 58L Cylinder Material Aluminum For Use With Any and All OEM Gas Detectors Connection Size C-10 Max Pressure 500 psi Cylinder Dia 3-17/32 In. Cylinder Height 14-1/4 In. Accuracy +/-5 Percent Calibration Certificate NIST