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The emission of the so-called extreme blazars challenges the particleacceleration models. The hardness of its spectrum, $<2$, demands extremeparameters using the standard one-zone SSC model in the high energy band. Someauthors use both two-zone or hadronic/leptohadronic models to relax theseextreme values. In this work, we present a leptohadronic two-zone model withexternal radiation fields to explain the broadband emission, where thecontribution of two components forms the hard-spectrum in the $\gamma$-raysband. The first is produced by the photopion process, where accelerated protonsin an inner blob located close to the core interact with the X-ray photonscoming from a pair plasma. This mechanism will be responsible for $\gamma$-raysin the TeV's energies range. The second contribution is produced by an outerblob, which corresponds to the source of X-rays and $\gamma$-rays with sub-TeVenergies via the standard SSC and EIC model. We exemplify our model with theprototype extreme blazar 1ES 0229 +200 obtaining a good description of itsspectral energy distribution.

Two-zone model as origin of hard gamma-rays spectrum in extreme BL Lacs