MIL-DTL-38999 Series I connectors feature up to 128 environmentally sealed contacts in an insert, ideal for harsh environments with an operating temperature range of -65 °C to 200 °C. This connector family offers front wall mount, rear wall mount, and jam nut receptacles with RFI grounding plugs, available in 9 shell sizes and 52 insert arrangements. Utilizing M39029 rear release crimp contacts, it accommodates sizes 22D, 22M, 22, 20, 16, and 8 for coax and twinax applications. Constructed with high-strength aluminum shells, these connectors come in various plating options including light iridescent yellow cadmium, olive drab cadmium, electroless nickel, and black anodized aluminum, with RoHS certified cadmium-free finishes available. Suitable for military and harsh environment applications, these connectors ensure reliable performance with a service rating of M, Twinax, and a mating life of 500 cycles.