The 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 configurations including front and rear wall mount, jam nut, and box mount receptacles. Available in 9 shell sizes and 52 insert arrangements, they use M39029 rear release crimp contacts. Constructed with aluminum shells and offering plating options such as electroless nickel and cadmium finishes, these connectors ensure reliable performance. With a service rating of I, they are suited for demanding applications that require durability and environmental resistance.