MIL-DTL-38999 Series I connectors feature up to 128 contacts in an environmentally sealed insert, designed for harsh environments with an operating temperature range of -65 °C to 200 °C. Offering front wall mount, rear wall mount, and jam nut receptacles with RFI grounding plugs, this connector family comes in 9 shell sizes and 52 insert arrangements. Utilizing M39029 rear release crimp contacts, they ensure secure connections in sizes 22D, 22M, 22, 20, 16, and 8 (including coax and twinax). Constructed with high-strength aluminum shells, these connectors are available in various plating options such as light iridescent yellow cadmium, olive drab cadmium, electroless nickel, and black anodized aluminum, including RoHS certified cadmium-free finishes. Ideal for military and industrial applications, they provide reliable performance with gold-plated contacts, a service rating of I, and environmental resistance.