MSA 803499 equivalent by GASCO R11 Refrigerant Calibration Gas 100 PPM R11 Balance Nitrogen contained in a 103 Liter Steel Disposable Cylinder, For Use with Any and All Gas Detectors, Cylinder connection C-10, Calibration Certificate NIST, Made in the USA, Calibration Refrigerant Gas is intended for use in Calibrating Refrigerant Gas Detection Equipment Only. NOT INTENDED FOR CHARGING Nitrogen CONDITIONING EQUIPMENT