The D38999 series circular connectors cover multiple sub-series with bayonet coupling and threaded coupling structures. Adopting scoop-proof housing and self-locking mechanism, they prevent damage to contacts during blind mating. The connectors operate within a wide temperature range and deliver outstanding resistance to vibration, shock and salt spray corrosion. The metal shell provides effective EMI shielding, and reliable sealing performance can be maintained after full mating, suitable for complex environments with extreme temperature, high humidity, dust and salt mist. Crimp and solder contacts are available, with complete male and female configurations. Various backshells and cable assemblies can be matched for assembly.