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. Designed for harsh environments, they come in various styles including front and rear wall mount and jam nut receptacles with RFI grounding plugs. With 9 shell sizes and 52 insert arrangements available, they use M39029 rear release crimp contacts in sizes 22D, 22M, 22, 20, 16, and 8. Encased in high-strength aluminum shells, these connectors offer plating options such as light iridescent yellow cadmium, olive drab cadmium, electroless nickel, and black anodized aluminum, including RoHS certified cadmium-free finishes. Perfect for military applications, these connectors are reliable with a maximum operating temperature of 150 °C, a minimum of -65 °C, and a mating life of 500 cycles, ensuring durability in demanding conditions.