D38999/20WG35SN is a MIL-DTL-38999 Series III subminiature connector featuring a threaded 360° turn coupling mechanism and environmentally sealed design for harsh environment applications. The connector is available with multiple shell materials including stainless steel, aluminum, and composite, with shell plating options such as electroless nickel, nickel PTFE, black zinc-nickel, and olive drab cadmium. It supports up to 187 maximum signal contacts with standard contact sizes of 23, 22, 20, 16, 12, 10, and 8, accommodates shell sizes 9 through 25, and offers contact styles including crimp, solder cup/eyelet, and PCB tail. Operating temperature range extends from -65°C to +200°C depending on shell finish, with a standard durability rating of 500 mating cycles. This connector is widely used in aerospace, defense, and marine systems where scoop-proof, environmentally sealed connections with EMI control via spring fingers are essential.