The MIL-DTL-38999 Series I connectors feature up to 128 contacts housed within an environmentally sealed insert, designed for harsh environments with operating temperatures ranging from -65 °C to 200 °C. Offering front wall mount, rear wall mount, and jam nut receptacles, as well as RFI grounding plugs, this connector family includes a variety of shell sizes and insert arrangements. Utilizing M39029 rear release crimp contacts, they are available in sizes 22D, 22M, 22, 20, 16, and 8 for coax and twinax applications. Constructed with high-strength aluminum shells, they come with plating options such as light iridescent yellow cadmium, olive drab cadmium, electroless nickel, and black anodized aluminum, including RoHS compliant finishes. Ideal for military and industrial use, these connectors offer reliable performance with their bayonet coupling, gold-plated contacts, and environment-resistant design.