MIL-DTL-38999 Series I connectors feature up to 128 contacts in an environmentally sealed insert, designed for harsh environments with an operating temperature range of -65 °C to 200 °C. Available in various shell sizes and insert arrangements, they offer front and rear wall mount options, along with jam nut receptacles. Utilizing M39029 rear release crimp contacts, these connectors ensure secure connections. Constructed with high strength aluminum shells and plated with options like gold, electroless nickel, and cadmium-free finishes, they provide durability and reliability. With a bayonet coupling and a service rating of M, these connectors are suitable for demanding applications requiring environment resistance.