The 9-103326-0-06: All 12 positions are loaded, so every pin is present for the BOM circuit count. Being unshrouded means there is no alignment wall around the pins — the mating receptacle must be guided by the housing or a separate shroud.
Unshrouded vs Shrouded: Why It Matters for the Fit
Unlike the shrouded 1379030-3 (12 positions, friction lock, 0.100" pitch) which has a four-wall shroud and a board lock, this 9-103326-0-06 is unshrouded with a push-pull fastening. The shrouded version adds alignment and a locking feature for vibration resistance, but takes up more board space. If your existing harness uses an unshrouded receptacle, this header is the direct fit.