MIL-DTL-38999 Series II connectors are designed for harsh environments, featuring up to 128 contacts in an environmentally sealed insert. With an operating temperature range of -65 °C to 200 °C, these connectors offer durability in extreme conditions. Available in various mounting styles such as front and rear wall mount, jam nut, and box mount receptacles, they provide flexibility for different applications. The connectors come in 9 shell sizes and 52 insert arrangements, utilizing M39029 rear release crimp contacts. Made of aluminum, they are offered in plating options including electroless nickel and cadmium finishes, with RoHS certified cadmium-free options available. Suitable for military and industrial use, these connectors ensure reliable performance with features like gold contact plating, bayonet coupling, and high mating cycles.