Three-dimensional isosurface density contours of the model UNI-A (top left), HEL2-A (top right), UNI-B (bottom left), and HEL2-B (bottom right) at t/t_a = 3.75 for a direction along a line of sight inclined at 20° with the jet axis. The color bars represent the jet density ρ/ρ₀. While the UNI cases have a turbulent flow structure as they only experience the KH instability, the HEL2 cases have a clearly identifiable jet boundary as they are relatively stable.