Radius of the PWN (R_pwn) with respect to the evolutionary state of a Sedov SNR, given by the radius of the forward shock R_snr (Eq. (4)). We show the results for n₀ = 10 (top) and 1 cm⁻³ (bottom). The number next to each curve is log(Ė), i.e., the spin-down energy of the powering pulsar. The filled circle is the size of the SNR and the PWN G29.4+0.1 for a distance of 6.5 kpc, while the dotted line gives R_snr and R_pwn for the distance range between 5.5 and 7.5 kpc.