The Sejong the Great class destroyers (Hangul: 세종대왕급 구축함), also known as KDX-III, are guided missile destroyers for the Republic of Korea Navy by Hyundai Heavy Industries. On May 25th, 2007, the ROK Navy has commissioned the ship for test run. It will be deployed for naval operations in 2009 after one-and-a-half years of test operations. ROK Navy plans to build up to 6 more of the same type. 2 ships in each side of the ocean.
The ship features the advanced Aegis combat system (Baseline 7 Phase 1 - Advanced Processor (4800 MIPS) and Distributed Processor (1600 MIPS)) combined with AN/SPY-1D multi-function radar antennas.

The Sejong the Great class is the third phase of the Republic of Korea Navy's KDX (Korean Destroyer eXperimental) program, a substantial shipbuilding program, which is geared at enhancing ROKN's ability to successfully defend the maritime areas around Korea from various modes of threats as well as becoming a blue-water navy

General Characteristics
Cost: ~US$923 million
Displacement: ~7,700 tonnes hull displacement
~10,000 ± 290 tonnes full load
Length: 544 ft (165.9 m)
Beam: 69 ft (21 m)
Draft: 46 ft (14 m)
Propulsion: 4 General Electric LM2500 COGAG;
two shafts,
100,000 total shaft horsepower (75 MW)
Speed: 30+ knots (56+ km/h)
Range: 5,500 nautical miles
Complement: 300-400 crew members
Armament: • One 5 inch (127mm/54) Mk-45 Mod 4 (lightweight gun)
• One 30 mm Goalkeeper CIWS
• One RIM-116 Rolling Airframe Missile launcher
• SM-2 Block IIIB in Mk. 41 80-cell Vertical Launching System
• Four SSM-700K Hae Sung (해성--"Sea Star") long-range anti-ship missile launchers with four missiles in each launcher
• 32 Hyunmoo IIIC (현무-3--"Guardian of the Northern Sky") land-attack cruise missiles + 16 K-ASROC, known as Hong Sahng-uh (홍상어--"Red Shark") in domestic 48-cell Vertical Launching System
• 32 K745 LW Cheong Sahng-uh (청상어--"Blue Shark") torpedos

Aircraft: • Two Westland Lynx Mk.99 ASW helicopters with full accomandations including hangars
(source from http://en.wikipedia.org/wiki/KDX-III)