D38999/20WC35SA 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 multiple shell materials including stainless steel, aluminum, and composite options, with various plating finishes such as electroless nickel, nickel PTFE, black zinc-nickel, and olive drab cadmium to meet corrosion resistance requirements. The connector accommodates up to 187 maximum signal contacts with standard contact sizes of 23, 22, 20, 16, 12, 10, and 8, using AS39029 contact type in crimp, solder cup, eyelet, or PCB tail styles. Operating temperature range extends from -65°C to +200°C depending on shell finish selection, with a standard durability rating of 500 mating cycles. This connector is ideal for mission-critical applications requiring reliable electrical connections in demanding environments with EMI control through spring finger design and hermetic sealing options.