MIL-DTL-38999 Series II connectors offer robust performance for harsh environments, featuring up to 128 contacts in an insert with environmental sealing. Operating between -65 °C and 200 °C, these connectors are versatile with 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 different sizes. Constructed with aluminum shells and plated with options like electroless nickel, these connectors ensure reliable connectivity. With a bayonet coupling design and EMI/RFI shielding, they meet stringent military specifications for durability and performance.