The 1-178140-2: This is a 6-position, 2-row vertical header from TE's Dynamic D-3200 series, on a 0.200" (5.08mm) pitch with a row spacing of 0.300" (7.62mm). It's a shrouded - 4 wall design with a detent lock, meant for board-to-board or cable connections in general-purpose and industrial gear. The post tails are tin, for a reliable solder joint in the through-hole wave process.
Board Lock and Stack Height Fit
That's a practical detail for harness builders who don't want the header shifting before the solder solidifies. Mated stacking heights are 31.00mm to 32.50mm — that range tells you the mating receptacle's standoff tolerance. The 0.150" (3.81mm) post length is enough for a standard 1.6mm PCB with a through-hole solder fillet.