MSA 10150595 Equivalent by GASCO 60 PPM Carbon Monoxide, 20 PPM Hydrogen Sulfide, 1.45% Methane (29% LEL)(58% LEL Pentane Simulant), 15% Oxygen, Balance Nitrogen contained in a 650 liter factory refillable cylinder, For Use with Any and All Gas Detectors, Cylinder Connection: TBD Gas Specific, Calibration Certificate NIST, Made in the USA