MSA 10048789 Equivalent by GASCO, CO 60PPM, Pentane Equivalent 58% LEL (Methane 1.45%), O2 15%, Balance Nitrogen contained in a 116 Liter Aluminum Cylinder, For Use with Any and All Gas Detectors, Cylinder connection C-10 5/8"-18 UNF, Calibration Certificate NIST, Made in the USA