SDSS i, r, g image of Z7215 with LOFAR radio emission overlaid as contours. The LOFAR high-resolution (10 arcsec × 6 arcsec) emission is shown by white contours [3, 5, 16, 64, 128, 256, 512]  ×  σ where σ = 170 μJy beam⁻¹. The LOFAR diffuse emission after compact source subtraction (with a resolution of 40 arcsec × 34 arcsec) is shown in red colour and red contours where contours are [2, 4, 8, 16, 32, 64]  ×  σ and σ = 350 μJy beam⁻¹. Smoothed Chandra X-ray contours are also shown in cyan. Cluster galaxies with known spectroscopic redshifts are marked by coloured rings, where the colour represents redshift.