In the great battles of World War II, the crews of U.S. Navy carriers not only launched airplanes to inflict damage upon the enemy, they had to be ready and able to defend their ship against enemy air attack. A primary weapon in fleet air defense on carriers and other ships was the 40mm Bofors anti-aircraft gun, a twin-mount displayed here. The 40mm Bofors proved highly effective, particularly with the advent of Japanese kamikazes in 1944-45. In fact, between 1 October 1944 and 1 February 1945, half of all aircraft shot down by Navy surface ships were attributed to this weapon.