The MIL-DTL-38999 Series II connectors, with up to 128 contacts housed in an insert, are designed for harsh environments with operating temperatures ranging from -65 °C to 200 °C. These environmentally sealed connectors come in various configurations including front and rear wall mount, jam nut, and box mount receptacles. Available in 9 shell sizes with 52 insert arrangements, they utilize M39029 rear release crimp contacts for reliable connections. Constructed with aluminum shells and offering multiple plating options, such as gold, electroless nickel, and cadmium-free finishes, these connectors ensure durability and performance in demanding applications. Meeting military specification MIL-DTL-38999 II, they are ideal for use in aerospace, defense, and industrial settings requiring rugged and high-quality electrical connections.