Spectral constraints on the stellar parameters of the narrow-lined stripped star. The panels show the disentangled spectrum (black) compared to PoWR models with the best-fit parameters (T_eff = 13.5, kK, logg = 2.25). The models differ in composition: one assumes solar hydrogen, helium, and metal abundances (Asplund et al. 2021), while our fiducial model (blue) is He- and N-enriched, characteristic of a stripped star. The narrow H-Balmer absorption lines support a low surface gravity, while the stripped-star model provides a better fit to the He and N absorption features. Metal lines not present in the model spectra (e.g. Si II 4153, 4163 Å) were not included in the atomic line lists.