12.7 cm/40 Type 89 naval gun

The 12.7 cm/40 Type 89 naval gun was a Japanese anti-aircraft (AA) gun introduced before World War II. It was the Imperial Japanese Navy's standard heavy AA gun during the war.
The Type 89 was adopted by the IJN on February 6, 1932, and was the primary anti-aircraft gun on new aircraft carriers, battleships and cruisers, most commonly installed in twin gun mounts. As IJN ships were upgraded in the 1930s and 1940s, older AA guns such as 8 cm/40 3rd Year Type naval gun and 12 cm/45 10th Year Type naval guns were replaced with Type 89's.