MIL-DTL-38999 Series II connectors are designed for harsh environments, with up to 128 contacts in an insert and environmental sealing. Operating between -65 °C and 200 °C, these connectors feature various mounting options like 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. The connectors, offered in aluminum shells, come with plating options including cadmium-free finishes. With a bayonet coupling and gold contact plating, they ensure reliable connectivity in challenging conditions, meeting MIL-DTL-38999 II military specifications.