The 1073821 replacement gas cell O-ring, is a 2-029 Kalrez O-ring designed to seal the front (field) mirror of MultiGas 203X/603x Fourier Transform Infrared (FTIR) gas analyzers having a 70mL gas cell volume to the sample cell body. This perfluoroelastomer has been selected for its exceptional chemical resistance to a wide range of aggressive gases and its ability to withstand high operating temperatures (up to 191°C) in hot, wet sample streams. As part of routine gas cell maintenance, oring 149-0025 should be replaced whenever the field mirror is removed for cleaning. Field mirror sold separately. Quantity of one 1073821 o-ring included.