The silos fiberglass mod. SIA are characterized by two shells, the internal one is smooth conical shape and one of cylindrical shape, which allow the stored products to fall easily. Their modular design facilitates their logistics and consequently reduces transport costs. There are three models: the SIA AN version characterized by a short leg structure attached to a support ring in the center of the silo; the SIA GL version instead consists of long legs fixed to the silo through solid steel plates and finally the new SIA TQS model with the internal surface completely smooth and the structure with support ring for short legs. All the models mentioned are prepared for the screw conveyors or pneumatic filling and for the extraction of the product by gate bottom, screws or automatic systems.