Calibration Gas Gas Name Methane Air Gas Mixture 9800 PPM Methane (20 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