This mobile 90 mm cannon was designed in the late 1940s, and used by the U.S. Marines during the Korean War. It was capable of being parachuted into battle. But it was not widely adopted for a number of reasons. It provided no armor protection to its crew of four. The only piece of armor on it is the blast shield around the cannon. It was not amphibious. A total of 325 of them were manufactured and existing ones are now in museums or displayed at National Guard buildings. Others had the cannon removed to provide a tank driving vehicle for training.