In attempting to match North Korean armored capabilities (though from more of an advanced technology perspective), South Korea developed a modern infantry fighting vehicle - the "Korea Next-Generation Infantry Fighting Vehicle" (KNIFV) - that allows its armored formations flexibility in tactics while providing the rugged cross-country capabilities required of military vehicles managing the rough Korean landscape. Work on the type began in 1999 to which successful evaluation of the prototype XK21 produced the official "K21" designation (the vehicle is also known as the "K300"). The South Korean IFV began service in 2009 and it is expected that several hundred of the type will eventually be procured. Serial production is being handled by Doosan DST of South Korea.
Outwardly, the 27.5-ton K21 showcases a conventional arrangement with a basic hull design lacking a notable superstructure to promote the shallowest possible profile. The driver manages a position in the front-left of the hull with the powerpack to his right. This arrangement clears the middle-rear of the vehicle for installation of a powered turret and passenger cabin. As such, the turret houses a 40mm autocannon complete with two integrated banks of electrically-launched smoke grenade projectors along the front-side facings. The turret is further stocked with advanced tracking and vision equipment along its roof which help to increase accuracy at range (even when on-the-move) while providing point-defensive measures against incoming threats to vehicle and crew. Some 200 x 40mm projectiles are carried for the main gun. Self-defense is through a 7.62mm machine gun in a coaxial mounting. To counter the threat posed by modern combat tanks, the K21 is outfitted with 2 x anti-tank guided missile launchers which supply armor-defeating capabilities at range. The base operating crew is three - the driver, gunner and vehicle commander - while the integrated passenger area at the rear of the vehicle can seat up to nine combat-ready infantry. A fully automatic fire suppression system ensures crew survivability in the event of an onboard fire and protects from lethal ammunition explosions.
Power for the K21 is supplied through a Doosan D2840LXE series diesel-fueled engine of 740 horsepower. This supplies the vehicle with a top speed of 70 km/h on ideal surfaces (less-so when going cross-country) and an operational range of 500 km/h. The hull is suspended on an "in-arm" suspension system which provides the needed cross-country mobility in keeping with mechanized doctrine. The K21 also features inherent amphibious capabilities through a specially developed buoyancy system.
The K21's armor is constructed of a fiberglass/ceramic armor combination which allows for basic weight-saving measures while being able to defeat battlefield threats from 14.5mm heavy gun calibers. Additionally, the critical frontal facing of the vehicle is designed to defeat up to 30mm armor-piercing cannon rounds while the top facings provide survivability from incoming artillery "spray". Beyond that, the vehicle relies on its bevy of warning receivers, smoke grenade dischargers (to provide the vehicle its own smokescreen as needed) and optional Explosive Reactive Armor (ERA) block kits.
In terms of its expected battlefield role, the K21 fulfills the same function as the American M2 Bradley and British FV510 Warrior series of IFVs. This includes disembarking and embarking infantry while under fire while engaging all manner of threats in urban and open-field fighting environments. A powered door at the rear of the hull provides access to the passenger cabin, turret and driver's position while individual hatches are available for the driver and the turret crew. The Soviet-era BMP-3 of the North Korean Army is the direct competitor to the K21.
Indonesia is the only other known global operator of the K21, having secured an order for 22 examples.