9 pins at 1.25 mm — what the board sees
The 1734829-9: This is a 9-position, single-row header on 0.049" (1.25 mm) pitch — the tightest spacing in the HPI series for this circuit count, which means the board footprint is compact but the routing channel between pads is narrow. All nine positions are loaded, so there are no empty spots to confuse the wiring scheme.
Right-angle, shrouded, and through-hole
Through-hole solder tails (0.091" / 2.30 mm post length) give a stronger mechanical anchor than SMT for a cable that gets tugged.