The Yugo class submarine is a class of four midget submarines used primarily for infiltration and espionage by North Korea. The class is so named because it was built to plans supplied to North Korea by Yugoslavia in 1965. This class is a family of midget submarines which are not all identical. The displacement is either the standard 90 tons of the original Yugoslavian design for the early units, or 110 tons for the later units, while armament is either a pair of 400 mm torpedo tubes (early units) or a pair of 21 in short torpedo tubes (later units); however, all units have the same range: at on the surface and at submerged. Their final example was built in the 1980s, after which they were superseded by the Sang-O class submersibles. In 1998 one out of the 6 submarines was captured by the