D38999/26FJ35PN is a MIL-DTL-38999 Series III circular connector designed for harsh aerospace, defense, and marine environments. The connector features a threaded, scoop-proof, triple-start self-locking coupling interface with aluminum or stainless steel shell construction, providing excellent corrosion resistance and durability. It supports multiple contact configurations and insert arrangements, accommodating various signal, power, and control applications with contact ratings up to 3 amps per contact and dielectric withstand voltage of 1000 VAC. The connector operates reliably across extreme temperature ranges from -65°C to +200°C and withstands high vibration, fluid ingress, and vacuum environments. Common applications include avionics, missiles, sensors, fuel tank systems, down-hole drilling equipment, and sealed vacuum chambers where rugged, reliable electrical interconnection is critical.