Calibration Gas Gas Name Carbon Monoxide Methane Oxygen Nitrogen Gas Mixture 50 PPM Carbon Monoxide 0.35 Percent Pentane (25 Percent LEL) Balance Air Background Gas Air 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