MIL-DTL-38999 Series I connectors feature up to 128 contacts in an environmentally sealed insert, designed for harsh environments with an operating temperature range of -65 °C to 200 °C. Included in this connector family are front wall mount, rear wall mount, and jam nut receptacles, along with RFI grounding plugs. Available in 9 shell sizes and 52 insert arrangements, these connectors use M39029 rear release crimp contacts in various sizes, including coax and twinax options. Constructed with high strength aluminum shells, they offer multiple plating options such as light iridescent yellow cadmium, olive drab cadmium, electroless nickel, and black anodized aluminum. RoHS certified cadmium-free finishes are also available. The MS27496 connectors are designed for box mounting with a bayonet coupling, suitable for military and industrial applications requiring durability and reliability in extreme conditions.