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, making them ideal for a wide range of applications. Available in 9 shell sizes and 52 insert arrangements, they use M39029 rear release crimp contacts in various sizes, including coax and twinax. 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. With RoHS certified cadmium-free finishes, these connectors offer reliable performance for critical military and industrial systems.