MSA 10103262 Equivalent by GASCO, 60PPM CO, 1.45% Methane, 15% O2, 2.5% CO2, 20PPM Hydrogen Sulfide 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