MIL-DTL-38999 Series I connectors feature up to 128 contacts in an environmentally sealed insert, designed for extreme conditions with an operating temperature range of -65 °C to 200 °C. This harsh environment connector family includes front and rear wall mount options, as well as jam nut receptacles and RFI grounding plugs. Available in 9 shell sizes and 52 insert arrangements, they use M39029 rear release crimp contacts in various sizes. Constructed with high strength aluminum shells, these connectors offer plating options such as electroless nickel and cadmium finishes, with RoHS certified cadmium-free alternatives. Ideal for military and industrial applications, they provide reliable connectivity with a bayonet coupling feature.