 They finally had a better electronic suite and a 76 mm gun with high rate of fire, along with newer P-270 Moskit and Kh-35 supersonic missiles, AK-630 CIWS, and 'Bass Tilt' radars.Fewer were built however, and so the Osas, after replacing the old Komars, remained widely in service up to the turn of the 21st century.About 175 Osa I and 114 Osa II boats were built for the Soviet Navy, the last were decommissioned in about 1990 in the main Soviet fleet.