MIL-DTL-38999 Series II connectors feature up to 128 contacts in an insert, offering environmental sealing and a wide operating temperature range from -65°C to 200°C. These connectors, designed for harsh environments, 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 in sizes 22D, 22M, 22, 20, 16, and 12. Constructed with aluminum shells, they come with plating options like cadmium and nickel, meeting RoHS compliance standards. With a straight plug design, EMI shielding, and bayonet coupling, these connectors ensure reliable performance in military and industrial applications, featuring a male pin contact style and a service rating of M for environment-resistant operations.