Sub-halo central velocity dispersion function derived from our lens models for MACS 1206, MACS 0416 and AS1063 with kinematic prior based on measured velocity dispersions of cluster members. Previous models with no kinematic prior for AS1063 and MACS 0416 are shown for comparison. Data points correspond to median galaxy counts in 35 km s⁻¹ bins, drawn from the posterior distributions of sub-halo model parameters. Errors also include Poissonian number statistics in each bin. Only galaxies within a cluster-centric radius of 0.16 × R_200c are included (see Table 1). The top axis gives the total mass related to the central velocity dispersion by Eq. (10) (see text).