MIL-DTL-38999 Series II connectors feature 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 and rear wall mount, jam nut, and box mount receptacles, they offer versatility in installation. These connectors come in 9 shell sizes and 52 insert arrangements, accommodating M39029 rear release crimp contacts in sizes 22D, 22M, 22, 20, 16, and 12. Constructed with aluminum shells and offered in different plating options, such as gold and electroless nickel, they ensure reliable performance in demanding applications. Compliant with military specification MIL-DTL-38999 II, these circular connectors are suitable for use in aerospace, defense, and other rugged environments where durability is essential.