MIL-DTL-38999 Series I connectors are designed for harsh environments with up to 128 contacts housed in an insert, featuring front wall mount, rear wall mount, and jam nut receptacles. These connectors, compliant with military specification MIL-DTL-38999 I, are environmentally sealed and offer reliable performance in temperatures ranging from -65 °C to 200 °C. Available in 9 shell sizes and 52 insert arrangements, they utilize M39029 rear release crimp contacts in various sizes, including coax and twinax. Constructed with high-strength aluminum shells, they come with a range of plating options, such as electroless nickel and cadmium finishes. These connectors, with a service rating of I, ensure durability and conductivity, making them ideal for demanding applications.