Totally 19 unites built at the Stocznia Polnocna yard, Gdansk, Poland with yard numbers 1301-130/19 with a 20th unit never completed. Names SR-28 (1984). SR-59 (1984), SR-478 (1984-2013), SR-479 (1984), SR-541 (1985). SR-74 (1985-2004). SR-548 (1987), SR-568 (1987-1997), SR-569 (1988), SR-120 (1987), SR-570 (1989). SR-137 (1988). SR-933 (1989), SR-936 (1990), SR-939 (1988), SR-216 (1988), SR-245 (1991) and SR-253 (1991-2000). With a displacement pf 1.811 (standard)-2.096 (full load) and as dimensions 69,5 x 13,8 x 3,98 metres. Machinery consists of 2-1.470hp Zgoda-Sulzer AL25D diesels allowing a sped of 13.6 knots and a range of 1.000 nautical miles at maximum speed. Crew numbered 45 men. Three units serve(d) in other navies, namely the Kapitan 1 Rang Dimitar Dobrev (pennant 206) in Bulgarian service, the Project B890511 the former SR-253) in Polish service since March 2000 and the Balta U811 (the former SR-568) since 1 August 1997 in Ukrainian service.
