D38999/20WB98SN is a MIL-DTL-38999 Series III subminiature connector designed for rugged, harsh environment applications in aerospace, defense, and marine industries. The connector features a threaded 360° turn coupling mechanism with scoop-proof design and environmental sealing to protect against contamination and moisture ingress. It supports shell materials in stainless steel, aluminum, and composite construction with multiple plating options including electroless nickel, nickel PTFE, black zinc-nickel, and olive drab cadmium finishes. The connector accommodates up to 187 maximum signal contacts using AS39029 contact type in crimp, solder cup/eyelet, or PCB tail styles, with shell sizes ranging from 9 to 25 and contact sizes of 8, 10, 12, 16, 20, 22, and 23. Operating temperature range extends from -65°C to +200°C depending on shell finish selection, with standard durability of 500 mating cycles and higher durability versions available. This connector is ideal for mission-critical applications requiring reliable electrical connections in extreme environmental conditions.