MIL-DTL-38999 Series I connectors feature up to 128 contacts housed in an insert, offering environmental sealing and a wide operating temperature range of -65 °C to 200 °C. The harsh environment connector family includes front wall mount, rear wall mount, and jam nut receptacles, along with RFI grounding plugs. Available in 9 shell sizes and 52 insert arrangements, they utilize M39029 rear release crimp contacts in various sizes. Constructed with high-strength aluminum shells, these connectors come with a range of plating options such as light iridescent yellow cadmium, olive drab cadmium, electroless nickel, and black anodized aluminum, including RoHS-certified cadmium-free finishes. Suitable for military applications, they are designed for durability, with a service class rating of E and a mating life of 500 cycles, ensuring reliable performance in demanding environments.