The 213597-4 is a 37-position circular plastic receptacle connector assembly designed for industrial applications requiring reliable circular connectivity. It features a metal shell with size 28, keyed mating alignment, and threaded coupling (1-7/16-18 UNEF 3B thread) for secure panel mounting with a flange and mounting holes. The connector includes 37 signal positions with socket-type contacts plated in gold (30 µm) on the mating area and tin over copper plating on through-hole termination posts (16.38 mm length), suitable for solder attachment. The assembly is RoHS and ELV compliant, wave solder capable to 260°C, 240°C, and 265°C, and is designed for printed circuit board applications where robust environmental sealing and high-density signal connectivity are required.