Radial velocity and [Fe/H] of our targets stars overplotted to the field star distribution, visualized as a linearly-scaled density distribution of arbitrary units (blue contours). Stars within the tidal radius of H4 are shown in red. Importantly, three of them group within the parameter space where we expect cluster members (black box). Black symbols are targets outside the tidal radius, which are purposefully selected to be metal-poor and therefore are not representative of the actual field star distribution.