SED of DES0141−54 from the radio to X-ray frequencies: the solid blue line shows the theoretical blazar model; the dashed black line is the spectrum of an accretion disk, together with the IR torus radiation and the X-ray emission produced in the hot corona; the solid light green line refers to the synchrotron emission; the grey long dashed line is the SSC component. The vertical orange line marks the position of the Ly-α break. As described in Ghisellini & Tavecchio (2009) the model does not reproduce the radio part of the SED because the jet emitting region that interacts with the external photons is compact and therefore auto-absorbed at low frequencies. We also report in green the Fermi/LAT sensitivity curve after 10 years (at 5σ) that shows that our predictions are consistent with a non detection by Fermi.