MIL-DTL-38999 Series I connectors feature up to 128 contacts in an insert, designed for harsh environments with an operating temperature range of -65 °C to 200 °C. Available in various shell sizes and insert arrangements, they offer front wall mount, rear wall mount, and jam nut receptacles with RFI grounding plugs. These connectors use M39029 rear release crimp contacts in sizes 22D, 22M, 22, 20, 16, and 8, including coax and twinax options. Constructed with high-strength aluminum shells, they come in plating options such as light iridescent yellow cadmium, olive drab cadmium, electroless nickel, and black anodized aluminum, with RoHS certified cadmium-free finishes. Suitable for military and industrial applications, these connectors provide reliable performance in demanding conditions.