Sketch of the possible geometry and physical scales of the system. While we do not constrain the distance to the PDLA, typical values of known systems are in the range of tens to hundreds of kiloparsecs. This would imply a distance between common sightlines to each quasar source of ∼0.5 pc, and 6 kpc for sightlines between each source. We note that the PDLA might not necessarily cover both quasars because our spectra are not deep enough to confirm this.