MIL-DTL-38999 Series II connectors offer reliable connectivity in harsh environments, featuring up to 128 contacts with a wide operating temperature range of -65 °C to 200 °C. These environmentally sealed 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 utilize M39029 rear release crimp contacts for secure connections. Constructed with durable aluminum shells and offered in multiple plating options including cadmium and nickel, these connectors ensure optimal performance. With a bayonet coupling mechanism and gold contact plating, they guarantee 500 mating cycles. RoHS compliant finishes are also available, making them suitable for diverse applications requiring high reliability in extreme conditions.