Region of 18 × 18 × 2 comoving Mpc h⁻¹ at redshift 0.25 containing three clusters. Dots represent the comoving positions of galaxies. The different panels depict the definition of the overlapping (red) and the isolated (black) regions in each cluster, marked with black circles that represent its 2 R₅₀₀, 4 R₅₀₀, and 6 R₅₀₀. Red circles represent r_ov = 6 R₅₀₀ of the neighbouring clusters, and the crosses mark the cluster centres. Mass M₅₀₀ of the considered cluster is displayed in each panel.