Comparison of the observed photometry (black dots) and spectrum (red line) of WISE1810 to LOWZ models (Meisner et al. 2021). Solar (blue) and low-metallicity [Fe/H] = −1.5 (orange) models are computed for T_eff = 800 K, log g = 5.0 dex and a solar C/O ratio. The blue wing of the H band and the W2 photometry are reasonably replicated by the metal-depleted theoretical spectrum. All data are normalised between 1.5 and 1.6 μm. The wavelength axis is in the logarithmic scale.