Theoretical parallaxes of Galactic Type II Cepheids in the Gaia database, as obtained from inversion of the theoretical PWZ relation in the Gaia bands, versus Gaia astrometric values, as corrected for the Lindegren et al. (2021) offset. In each panel, we show the results obtained assuming the labelled metal abundance in the PWZ relation. The bottom plot of each panel shows the corresponding residuals computed as ϖ^DR3 + L21 − ϖ^teo.