MIL-DTL-38999 Series II connectors offer up to 128 contacts in an environmentally sealed insert, designed for harsh environments with an operating temperature range of -65°C to 200°C. Available in various mounting options including front wall mount, rear wall mount, jam nut, and box mount receptacles, they feature thin walls and restricted lengths. With options for straight, RFI grounding, and standard plugs, these connectors come in 9 shell sizes and 52 insert arrangements, utilizing M39029 rear release crimp contacts. Constructed with aluminum shells, they offer plating choices such as light iridescent yellow cadmium, olive drab cadmium, electroless nickel, and black anodized aluminum, including RoHS certified cadmium-free finishes. Suitable for military and industrial applications, these connectors provide reliable performance with a 500-cycle mating life and conductive pin contacts, meeting stringent environment-resistant standards.