Left: J0315–0024 field. H I detected in the BCD target J0315–0024 and its companions KUG 0313–006, UGC 2628, and WISEA J031630.50–002345.1 marked on a SDSS g-band image with the blue contours showing the VLA BC-configuration H I at column densities of 1.7, 3.5, 7.0, 14.0, 21.0, 28.0, and 35.0 × 10²⁰ atoms cm⁻², with the first contour at 3 σ. The small ellipse in the bottom left corner indicates the size and orientation of the VLA BC-configuration 9.5″ × 8.3″ FWHP synthesised beam. The large circle shows the Effelsberg 9′ FWHP beam. Right: H I velocity field with contours separated by 5 km s⁻¹, with velocities shown by the colour scale.