MIL-DTL-38999 Series I 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 shell sizes and insert arrangements, they come in high-strength aluminum shells with options for plating finishes such as electroless nickel and cadmium. The connectors, including front and rear wall mount receptacles and jam nut plugs, utilize M39029 rear release crimp contacts. With gold-plated contacts and a bayonet coupling, they ensure reliable connectivity in demanding applications, meeting military specification MIL-DTL-38999 I standards.