The Phalanx CIWS is a close-in weapon system for defending 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 (0.79 in) Gatling gun mounted on a swiveling base, the Phalanx is used by the United States Navy on every class of surface combat ship, by the United States Coast Guard aboard its Hamilton-class and Legend-class cutters and the navies of 16 allied nations.
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 from Star Wars, and in the Royal Navy as Daleks, after the aliens from Doctor Who.
Read more about Phalanx CIWS: History, Design, Operation, Operators, Specifications (Block 1A/B), Similar Systems