Edge-on projection of the FP in the B-band. The black points represent the galaxies with z < 0.35, and the open red diamonds are the objects with z > 0.35. The parameters a, b, and the zero-point were obtained by fitting the galaxies at z > 0.35, through a non-linear weighted least-squares fit. The green squares added in the right panel are the early-type galaxies of Gebhardt et al. (2003) with redshifts in the range 0.3 < z < 1.0.