Its 0.250-inch (6.35mm) pitch and shrouded 4-wall housing guide the mating receptacle and protect the male pins during handling and mating.
The 6.35mm pitch is the primary footprint constraint: the through-hole solder tails are spaced 0.250-inch apart, and the insulation height of 0.550-inch (13.97mm) sets the clearance above the board.
