Same as Fig. 3 but displaying the contact discontinuity of the pulsar wind material (50% in number density) within the surrounding supernova ejecta (cyan) at time 80 kyr with θ_mag = 0° (a) and θ_mag = 45° (b). The figure shows the plerion at an advanced age of their evolution, when the deviation exerted by the circumstellar medium on the morphology of the pulsar wind nebula is at maximum. An animated version of this figure is available as online material.