MIL-DTL-38999 Series I connectors feature up to 128 contacts in an environmentally sealed insert, with a wide operating temperature range of -65 °C to 200 °C. Designed for harsh environments, they come in front and rear wall mount, jam nut receptacles, and RFI grounding plugs. Offered in 9 shell sizes and 52 insert arrangements, they use M39029 rear release crimp contacts in various sizes. These connectors boast high-strength aluminum shells with plating options like electroless nickel and cadmium finishes. RoHS certified options are available, making them suitable for diverse applications requiring durability and reliability.