MIL-DTL-38999 Series I connectors feature up to 128 contacts in an insert, offering environmental sealing and a wide operating temperature range of -65 °C to 200 °C. These harsh environment connectors come in various configurations including front and rear wall mount receptacles, jam nut receptacles, and RFI grounding plugs. With 9 shell sizes and 52 insert arrangements available, they utilize M39029 rear release crimp contacts in sizes 22D, 22M, 22, 20, 16, and 8. Constructed with high-strength aluminum shells, the connectors come with different plating options such as light iridescent yellow cadmium, olive drab cadmium, electroless nickel, and black anodized aluminum, catering to diverse application needs. The RoHS compliant variants provide cadmium-free finishes, ensuring environmental responsibility. Designed for military specifications, these connectors are reliable in demanding settings, with features like bayonet coupling, gold contact plating, and N keyway polarization. Suitable for use in Wall and Jam Nut Mounting receptacles and plugs, they offer robust connectivity with a mating life of 500 cycles.