Spectra of the CO(3–2) toward SPT 0125-47 (left) and SPT 2134-50 (right) showing the coverage of the red and blue bins used to investigate the effect of differential lensing, as described in Section 4.1. In both cases, the spectrum is shown in the top panel, and the residuals from the Gaussian fit are shown in the bottom panel. The dashed blue line shows the two Gaussian fit to the spectra. The dashed gray line in the top panel and the shaded gray region in the lower panel indicate the per-channel RMS. Additionally, the top axis in the top panel of each spectrum displays the corresponding frequency.