MIL-DTL-38999 Series II connectors are designed for harsh environments, featuring up to 128 contacts in an insert with environmental sealing. Operating between -65 °C and 200 °C, these connectors come in various mounting options like front wall, rear wall, jam nut, and box mount receptacles. Available in 9 shell sizes and 52 insert arrangements, they use M39029 rear release crimp contacts, offering versatility in applications. Constructed with aluminum shells and plated with options like cadmium and nickel, these connectors ensure durability and reliability. Ideal for military and industrial use, they meet stringent standards for performance in demanding conditions.