Right-angle orientation and board-edge clearance
The 2842124-3: Right-angle through-hole mounting places the header parallel to the PCB surface — the 0.157" (4.00 mm) mating pin length and 0.059" (1.50 mm) insulation height together define the z-height budget for the mating receptacle and the keep-out zone on adjacent layers. The unshrouded, push-pull fastening means no latch or shroud adds width to the footprint — useful for tight board-edge layouts where a shrouded header would overhang the board outline.