The MIL-DTL-38999 Series I connectors are designed for harsh environments, featuring up to 128 contacts in an insert with front wall mount, rear wall mount, and jam nut receptacles. Operating between -65°C and 200°C, these connectors are environmentally sealed for reliable performance. Utilizing M39029 rear release crimp contacts, they come in various shell sizes and insert arrangements for versatility. Constructed with high-strength aluminum shells and available in different plating options, including cadmium-free finishes, they ensure durable connectivity. Meeting military specifications, these circular receptacles are ideal for applications requiring secure and conductive connections in demanding settings.