Calibration Gas Gas Name Carbon Monoxide Methane Oxygen Nitrogen Gas Mixture 100 PPM Carbon Monoxide 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