MIL-DTL-38999 Series I connectors feature up to 128 contacts in an environmentally sealed insert, suitable for harsh environments with a wide operating temperature range from -65 °C to 200 °C. This connector family offers front wall mount, rear wall mount, and jam nut receptacles, along with RFI grounding plugs. Available in 9 shell sizes and 52 insert arrangements, they utilize M39029 rear release crimp contacts ranging from sizes 22D to 8 (coax and twinax). Constructed with high-strength aluminum shells and various plating options including cadmium-free finishes, these connectors are designed for durability and reliability in military and aerospace applications.