MIL-DTL-38999 Series I connectors, part of the rugged 38999 family, feature front wall mount, rear wall mount, and jam nut receptacles for secure connections in harsh environments. With up to 128 contacts housed in an insert, these connectors are environmentally sealed and can withstand temperatures ranging from -65 °C to 200 °C. Available in 9 shell sizes and 52 insert arrangements, they use M39029 rear release crimp contacts in various sizes, including coax and twinax options. Constructed with high-strength aluminum shells, they come with a choice of plating finishes such as light iridescent yellow cadmium, olive drab cadmium, electroless nickel, and black anodized aluminum, some of which are RoHS certified. These connectors, designed for military specifications, ensure reliable performance with their gold-plated contacts, bayonet coupling, and A keyway polarization. Suitable for back panel wall mounting applications, they are tested for 500 mating cycles, offering conductive connectivity and environmental resistance for critical operations.