GASCO | 34L-314S-NO2BS | X05NI83CA3408Y1|60 PPM CO, 1.45% Methane, 15% Oxygen, 10 PPM Nitrogen Dioxide, Balance Nitrogen contained in a 34 Liter Disposable Aluminum Cylinder, For Use with Any and All Gas Detectors, Cylinder Connection C-10, Calibration Certificate NIST, Made in the USA