2b thread class right-hand 3.855" overall length 0.605" overall width 40 thread quantity per inch contacts have nickel plating under the gold. unc thread series
Used on nuclear power plants. 1.240" overall length 30.7mm overall width instead of unthreaded mounting holes, this flange has unthreaded ovals, 0.128" wide by 0.173" long.
Used on 417 ft nsc (wmsl-750) coast guard vessels. voltage metering switch, 8 position, selects between 7 each shore power receptacles or "off" for nsc