Draeger 4594604 equivalent by GASCO 50% LEL Methane, 100 ppm CO, 10 ppm SO2, 17% Volume O2, Balance Nitrogen Contained in a 58L Liter Disposable Aluminum Cylinder, For Use with Any and All Gas Detectors, Cylinder Connection C-10, Calibration Certificate NIST, GASCO Calibration Gas is ISO 9001 Certified Made in the USA