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. These circular plugs are environmentally sealed and can operate in temperatures ranging from -65 °C to 200 °C. Compliant with military specifications, they boast high strength aluminum shells with various plating options including gold, electroless nickel, and cadmium free finishes. Utilizing M39029 rear release crimp contacts, they ensure secure connections with a mating type of bayonet. With a service rating of M for environment resistance, these connectors are ideal for demanding applications.