 This was to be a supplementary weapon for larger warships and as the main gun armament for minesweepers and auxiliaries.The twin gun version, ZIF-31, appears to have entered service with the Project 264 Minesweepers (T58 class) and the Project 310 (Don class) submarine support ships in 1958.In 1960, two other versions of the mounting appeared; a single gun ZIF-71 for the modernised Skoryy class destroyers and the quad ZIF-75 for the Krupny/Kanin class destroyers.