Right answer is Caproni-Vizzola F.4 ...
"Monoplane fighter, of mixed contruction with a semi-elliptical wing. It was developed in parallel with the very similar F.5, the latter being powered by a radial engine. Because the Asso 121 engine of the F.4 was disliked by the Regia Aeronautica, the F.4 was completed only in 1939, then powered by the Daimler-Benz DB 601A engine. It remained a prototype, because development of the more advanced F.6 was already underway."
