That thick tin layer handles a reasonable number of mating cycles for a board-level interconnect — think prototype rework or field-service swaps, not a daily-disconnect cable harness.
The 0.100" pitch and 0.100" row spacing put this on a standard 0.100" grid — the same footprint as legacy BergStik headers and most 0.100" IDC connectors. The overall contact length is 0.600" (15.24 mm), split into a 0.380" (9.65 mm) mating tail and a 0.120" (3.05 mm) solder post. That short post length means the header sits flush on the board — no long tails to trim or interfere with a backplane. For a 36-position dual-row header, the board real estate is about 1.8" long by 0.2" wide — a dense pin field for routing traces between the rows.
This is a straight through-hole header — no right-angle, no surface-mount, no press-fit.