  From the kinematics of 137 spirals we find that the DM halo density profiles
are self-similar at least out to R_opt and show core radii much larger that the
corresponding disk scale-lenghts. The luminous regions of spirals consist of
stellar disks embedded in dark halos with roughly constant density. With
respect to previous work, the present evidence is obtained by means of a robust
method and for a large and complete sample of normal spirals.
