The Phalanx CIWS is a close-in weapon system for defense against anti-ship missiles. It was designed and manufactured by the General Dynamics Corporation, Pomona Division (now a part of Raytheon). Consisting of a radar-guided 20 mm Gatling gun mounted on a swiveling base, the Phalanx has been used by multiple navies around the world, notably the United States Navy on every class of surface combat ship, by the British Royal Navy in its older escorts (where weight limits the use of the heavier Dutch Goalkeepers 30 mm CIWS), by the United States Coast Guard aboard its Hamilton-class and Legend-class cutters, and the navies of 16 allied nations.
[Source: U.S. Navy]
A land based variant, known as C-RAM, has recently been deployed in a short range missile defense role, to counter incoming rockets and artillery fire.
Because of their distinctive barrel-shaped radome and their automated nature of operation, Phalanx CIWS units are sometimes nicknamed "R2-D2" after the famous droid character from the Star Wars films.
