MIL-DTL-38999 Series II connectors are designed for rugged environments, with up to 128 contacts sealed for protection. Operating temperature ranges from -65 °C to 200 °C, ensuring reliability in extreme conditions. These connectors come in various configurations like front wall mount, rear wall mount, and jam nut receptacles, with options for straight, RFI grounding, and standard plugs. Featuring 9 shell sizes and 52 insert arrangements, they use M39029 rear release crimp contacts for secure connections. Constructed with aluminum shells and offered in different plating options like cadmium and nickel, they meet RoHS standards. Ideal for military and industrial applications requiring durable and high-performance connectivity.