What this 2-position header does that a standard pin strip can't
The 1586040-2: The 4.20 mm pitch gives you room to route 9 A per circuit at 600VAC without the thermal crowding you'd get on a finer-pitch header.
Sizing the current path and the mating half
At 9 A per circuit, the 1586040-2 carries more current than typical 4.20 mm pitch headers (many are rated 5-7 A). The locking ramp mates with the matching VAL-U-LOK receptacle housing. The 0.165" (4.20 mm) row spacing and 0.504" (12.80 mm) insulation height mean the cable plug clears board components below that height.