Calibration Gas Gas Name R134A Nitrogen Gas Mixture 99.1 PPM Refrigerant R134A Balance Nitrogen Background Gas Nitrogen 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