MIL-DTL-38999 Series I connectors feature up to 128 contacts housed in an insert and are designed for harsh environments with an operating temperature range of -65 °C to 200 °C. Available in various configurations including front wall mount, rear wall mount, and jam nut receptacles, they offer RFI grounding plugs for added versatility. With 9 shell sizes and 52 insert arrangements, these connectors utilize M39029 rear release crimp contacts in sizes 22D, 22M, 22, 20, 16, and 8 for coax and twinax applications. Constructed with high strength aluminum shells, they come in different 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 aerospace applications, these connectors provide reliable performance with gold-plated contacts, bayonet coupling, and environmental sealing to ensure durability in demanding conditions.