Left: Observed slit-spectra of the Ca I 4227 Stokes vector, whereby the horizontal blue and black dashed lines indicate the spatial regions considered for the inversion. Center and right: Context of the observation given by the continuum and magnetogram (clipped at ±50 gauss) image of HMI on board SDO. The cyan line represents the slit (width not to scale), with the red cross indicating its center, placed at a limb distance of μ = 0.43 (see magenta dashed lines). The blue and black crosses on the slit-spectra images mark the centers of two spatial regions, labeled as A and B, which were considered for the inversion.