Project 204 of which 66 units were built for the Soviet, Romanian and Bulgarian navies between 1960-1968, serving in the Soviet navy until the late 1980 and in the Bulgarian navy even in the 21st Century with the last 3 decommissioned in 2005. . Preceded by the Kronshtadt-class/Project 122bis and succeeded by the Pauk-class/Project 1241.2 Molniya-2. In the Bulgarian navy served the Khrabi, Strogi, Bezstrashni, Letjahhi, Bditelni and Naporisti and in the Romanian navy 3 units.
Displacement 508 9standard)-589 (full load) tons and as dimensions 59,4 x 7,9 x 2,0 metres pt 195 x 25.11 x 6.7 feet. The 2 gas turbines supplying 30.000shp and the 2 diesels supplied via 2 shafts 8.000 shp allowed a maximum speed of 38 knots. The range was with a speed of 10 knots 4.500 nautical miles and with maximum speed 520 nautical miles. The crew numbered 80 men. Armament consisted of 1x2-5,7cm/2,2 guns, and 4-40,6cm/16” anti submarine torpedo tubes although other unites of the class were armed with 2-53,3cm/2” torpedo tubes and 2 RBU-6000 anti submarine rockers (Romanian and early Soviet units had the RBU-2500).