The full 4-wall shroud and keying slot prevent mis-mating with non-keyed receptacles, and the short latch lock/eject hooks provide positive retention against cable pull-out without adding height to the mated pair.
With 50 positions loaded across two rows, the header occupies a 25-position-per-row footprint. The 0.110" (2.79mm) solder tail length suits standard 0.062" (1.6mm) PCBs — the tail protrudes enough for a reliable through-hole solder fillet without bottoming out on the opposite side. The 0.549" (13.94mm) insulation height and 0.639" (16.23mm) overall contact length set the mated stack height: expect the receptacle to sit roughly 0.240" (6.10mm) above the header body, which is the contact length available for mating. Keep this z-height in mind for enclosure clearance.