MIL-DTL-38999 Series I connectors feature up to 128 contacts in an insert, offering environmental sealing and a wide operating temperature range from -65 °C to 200 °C. This harsh environment connector family includes front wall mount, rear wall mount, and jam nut receptacles, as well as RFI grounding plugs. 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, these connectors come with plating options such as light iridescent yellow cadmium, olive drab cadmium, electroless nickel, and black anodized aluminum, with RoHS certified cadmium-free finishes. Suitable for military and industrial applications, they provide reliable performance with a service rating of I and a mating life of 500 cycles.