(taken from the photographic reference manual provided in kit).
Original conceived in 1915, as a little torpedo boat early prototypes were a failure due to the heavy weight of the torpedo. Soon afterwards, Italy entered WWI and more of the boats were ordered. Development never ceased, and by the end of WWI over 244 MAS's were in service. The first true torpedo MAS gained considerable fame by sinking the Austrian Battleships Wien and Szent Istvan.
Development of the boats continued thru the 20's and 30's. Speed was essential and improvements were made to the hull and more powerful engines installed. Finally the much sought after 40 knots was achieved in MAS 424 in 1928. Three 500 hp Isotta Fraschini Asso engines powered the boat.