100 PPM CO | 25 PPM H2S | 10 PPM SULFUR DIOXIDE | 0.35 % PENTANE (25% LEL) | 18 % OXYGEN | BALANCE NITROGEN | Contained in a 116L Liter Disposable Aluminum Cylinder, For Use with Any and All Gas Detectors, Cylinder Connection C-10, Calibration Certificate NIST, Made in the USA