The Otobreda 127mm/54 Compact (127/54C) gun is a dual purpose naval artillery piece built by the Italian company Oto Melara. It uses the 127mm round which is also used in the 5 inch/ 54 gun, albeit that this gun calibre is measured in United States customary units rather than metric. The gun uses an automatic loading system where 66 127mm rounds of various kinds can be stored ready-to-fire in three loader drums. The barrel is water-cooled. Currently the gun is still in use by navies around the world but it is slowly being replaced by the Otobreda 127/64 for new vessels, such as the German Navy's F125-class frigate and Italian Navy's FREMM.