Replacement mirror kit 1085930-002 is a routine maintenance kit designed for use with MultiGas 203X/603x Fourier Transform Infrared (FTIR) gas analyzers having a 70mL gas cell volume. This kit inlcudes a gas cell field (front) mirror with a 5.11m pathlength and MgF2, corrosion resistant, coating in addition to a replacement 1073821 Kalrez oring. (Gas cell windows sold separately)