Calibration Gas Gas Name Carbon Monoxide Hydrogen Air Gas Mixture 500 ppm Carbon Monoxide 600 ppm Hydrogen Balance Air Background Gas Air Cylinder Capacity 105L Cylinder Material Aluminum For Use With Any and All OEM Gas Detectors Connection Size C-10 Max Pressure 1200 psi Cylinder Dia 3-13/64 In. Cylinder Height 12-1/2 In. Accuracy +/-2 Percent Calibration Certificate NIST