Acunto ovens are designed with thick thermal insulation in the dome as well as beneath the baking surface to ensure high heat retention. The oven also has a heat soak layer of volcanic material directly from Mount Vesuvius which acts to store extra heat. The dome shape is based on a variant of the Pompeii oven design, which creates a swirling effect of intense top heat needed to create the signature blistered crust of a proper Neapolitan pizza.