The 0.100" (2.54mm) pitch and row spacing define the board footprint — this is a standard dual-row layout that lines up with nearly any 28-position, 2-row IDC or box-header receptacle on the same pitch. Tin-over-tin contacts are cost-effective for applications that do not require the corrosion resistance or cycle life of gold — expect reliable performance through a few dozen mating cycles in clean, indoor environments. The unshrouded design (no shroud around the pins) keeps the footprint compact and the header low-profile, but it offers no keying or polarization.
The phosphor bronze contacts carry the 5 A rating with adequate spring retention. The 0.120" (3.05mm) solder post length suits standard PCB thicknesses in the 0.062" to 0.093" range.