Central density of dark halos on scales from galaxies to clusters of galaxies. We take the data for dwarf galaxies (filled squares), LSB galaxies (open squares), and three distant clusters (open circles) from the work of Firmani et al. (2000) directly. Our derived central densities, ﹩\rho _{0}﹩, in the RDH profile for 45 MME clusters are shown by filled circles, for which the horizontal axis represents velocity dispersion rather than maximum rotation velocity (﹩V_{m}﹩), as for galaxies.