Calibration Gas Gas Name Carbon Monoxide Methane Sulfur Dioxide Oxygen balance Nitrogen Gas Mixture 50 PPM Carbon Monoxide 10 PPM Sulfur Dioxide 2.5 Percent Methane (50 Percent LEL) Balance Air Background Gas Air 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