3-747579-4 is a stepped ferrule designed for use with HDP-20 shielding hardware kits in AMPLIMITE D-subminiature cable connector assemblies. This ferrule is compatible with shell sizes 1-3 and accommodates cable diameters ranging from .324 to .375 inches, with an L dimension of .440 inches. The ferrule is constructed from steel with a tin-plated finish for corrosion resistance and reliable electrical shielding. It is designed for use with die set 543424-6 for proper crimping. Common applications include industrial machinery, medical instrumentation, computers and peripherals, and data storage systems where shielded D-subminiature connections are required.