Gasco | 58L-411-20.9 | X05NI78CP580015 | 25 % LEL Pentane [0.35%] 25 ppm hydrogen sulfide, 100 ppm carbon monoxide 20.9 oxygen 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, Made in the USA