The 98414-S06-12ULF: Contact finish is gold GXT™ on the mating surface at 15.0 µinch thickness — rated for repeated mating cycles without the fretting corrosion you'd see on tin.
Through-hole mounting with a 0.098" (2.50 mm) post length — the board hole diameter and solder fillet must accommodate the square pin cross-section. Row spacing is also 0.079" (2.00 mm), so the total footprint is a 2×6 grid with 2.00 mm pitch in both axes. The insulation height of 0.232" (5.90 mm) sets the z-height clearance above the board after mating. The keying slot in the shroud prevents mis-mating with non-keyed receptacles — useful when multiple similar headers sit on the same board and you need to guarantee the right cable goes to the right header.