CRIRES⁺ K-band spectra of Luhman 16A and B in orange and blue, respectively. Top panel : seven spectral orders covered in the K2166 wavelength setting. The telluric absorption is shown as transparent lines. Lower panels : zoom-in of the sixth order. The black observed spectra are overlaid with the best-fitting free-chemistry models in orange and blue. The mean scaled uncertainties are displayed to the right of the residuals in the bottom panel. The fits to the other spectral orders can be found in Appendix D.