MIL-DTL-38999 Series I connectors are designed for harsh environments, featuring up to 128 contacts in an insert with environmental sealing. Operating between -65 °C and 200 °C, they offer versatility and durability. Available in various shell sizes and insert arrangements, these connectors come in high strength aluminum shells with plating options including cadmium finishes. With RoHS certified cadmium-free options, they ensure compliance with environmental standards. The connectors, suitable for military applications, include front and rear wall mount receptacles and RFI grounding plugs, offering flexibility in installation. Utilizing M39029 rear release crimp contacts, they provide reliable connectivity with options for contact sizes 22D, 22M, 22, 20, 16, and 8 (coax and twinax). The bayonet coupling system facilitates easy mating, while the gold contact plating ensures optimal conductivity. With a service rating of I and ingress protection, these connectors meet stringent performance requirements for demanding environments.