The Molex 1731091061 is a 9-position male D-sub plug from the FCT 173109 series, using the standard DE-9 shell layout. It is the plug half of a classic DE-9 interconnect — the side that carries the male pins and mates with a 9-position receptacle (female) housing. Grounding indents on the shell mate with the receptacle's shield to bleed common-mode noise before it reaches the signal pins — a detail that matters in industrial or lightly noisy environments where the cable shield needs a low-impedance path to chassis ground.
Through-hole solder termination — the pins pass through the PCB and are wave-soldered on the opposite side. The unthreaded housing flange accepts a standard DE (E) footprint; the shell is steel with tin plating, giving a solid ground reference when soldered to the board's ground plane.