17L-399-S-5: 5 % CARBON DIOXIDE, 5 % METHANE, BALANCE NITROGEN CONTAINED IN A 17 LITER STEEL CYLINDER WITH A CGA 600 CONNECTION contained in a 17 Liter Disposable Steel Cylinder, For Use with Any and All Gas Detectors, Cylinder Connection CGA 600, Calibration Certificate NIST, Made in the USA