Synchrotron power of RHs at 1.4 GHz (P_{1.4 GHz}) vs. cluster mass M₅₀₀ (from Planck Collaboration 2016). Detected radio haloes reported in the literature measured at 1.4 GHz (see Martinez Aviles et al. 2016) are shown in black dots. The red line is the best fit for the black dots. The purple star corresponds to the radio halo on PSZ2 G284.97-23.69. The blue arrows correspond to detection limits appearing in Cassano et al. (2013) and references therein. The red arrows are the upper limits for the non-detections presented in this paper (see Table 4).