MIL-DTL-38999 Series II connectors are designed for harsh environments, featuring up to 128 contacts in an insert with front and rear wall mount options, jam nut, and box mount receptacles. Ideal for military applications, these connectors offer a wide operating temperature range from -65 °C to 200 °C. With various shell sizes and insert arrangements, they use M39029 rear release crimp contacts and come in aluminum shells with multiple plating options, including RoHS certified finishes. These connectors ensure reliable performance in demanding conditions, making them essential for aerospace and defense systems.