Halo radio synchrotron emission. We show P_synch at 1.4 Ghz for a VLA-like configuration, adopting a simple model for the relativistic electron population that assumes equipartition with the magnetic energy density (see text for details). Radio power rises rapidly with increasing halo mass, following an overall clear relation plus a small fraction of highly emitting outliers. Halo integrated synchrotron emission in TNG-Cluster is in the ballpark of observational results (Cassano et al. 2013).