Representative channel maps from the observed data cube of NGC 4217 and the different models that include the outer ring. Contour levels are −1.5, 1.5 (1.5σ), and 8.0 mJy beam^-1. The black contours show the observations, with negative contours as dashed grey. The green contours represent the final (B) model. Other models are shown as red contours. Because we want to highlight different features, the channels shown here are different from those in Fig. 17. The arrows highlight the projection along the major axis of the outer ring in the B+R1 model, which clearly disagrees with the data.