The VAL-U-LOK series uses a standard female socket contact.
How the 4.20mm Pitch and 3 Positions Drive the Fit
The 4.20mm pitch is the footprint anchor — the mating header's pins are on the same 4.20mm centers, so the board layout and the housing cavity spacing are locked to that dimension. The 3-position count means a 3-circuit harness or a 3-pin header mate. The single-row layout keeps the housing narrow, which helps in tight enclosures or when routing multiple wires side by side. No secondary lock is required for standard duty, but the latch is the primary retention, so check that the header side has the matching lock feature.