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 and rear wall mount receptacles, as well as jam nut receptacles with RFI grounding plugs. With 9 shell sizes and 52 insert arrangements available, they use M39029 rear release crimp contacts, ranging from sizes 22D to 8 for coax and twinax applications. Constructed with high strength aluminum shells, these connectors come with various plating options such as light iridescent yellow cadmium, olive drab cadmium, electroless nickel, and black anodized aluminum, some of which are RoHS certified. Suitable for military and industrial use, these connectors ensure reliable performance with a mating life of 500 cycles and an environment-resistant design for demanding applications.