MIL-DTL-38999 Series I connectors are designed for harsh environments, featuring up to 128 contacts in an insert with front wall mount, rear wall mount, and jam nut receptacles. These connectors are environmentally sealed and operate in temperatures ranging from -65 °C to 200 °C. Utilizing M39029 rear release crimp contacts, they come in 9 shell sizes and 52 insert arrangements, including sizes 22D, 22M, 22, 20, 16, and 8 (coax and twinax). Constructed with high strength aluminum shells, they offer a variety of plating options such as light iridescent yellow cadmium, olive drab cadmium, electroless nickel, and black anodized aluminum, with RoHS certified cadmium-free finishes available. With a straight plug configuration and gold contact plating, these connectors ensure reliable performance in demanding applications, meeting MIL-DTL-38999 I military specifications.