Comparison between W1 and W2 magnitudes from the best-fit models and WISE observations. Vertical dashed lines delineate the magnitude limits between which AGB stars are selected to derive the coefficients of calibration equations. Solid lines are the linear least-squares fits to the data points between lower limit and the WISE saturation limit. Dotted lines are the lines of the unit slope for reference. The error bars in the right corner indicate the median uncertainties in model magnitudes, including that caused by variability.