12-position, 3.30 mm pitch, shrouded header
The 3-1971906-6 is a TE Connectivity AMP Connectors Grace Inertia GIC header — 12 circuits in two rows at 3.30 mm pitch, fully shrouded on all four walls. The 3.30 mm pitch sets the board footprint and the mating receptacle spacing; it is wider than the common 2.54 mm pitch, so the PCB layout is specific to this series.
ROHS3 compliant. No official successor or pin-compatible alternative is listed from the original manufacturer.
The insulation height of 0.561" (14.25 mm) sets the z-height clearance above the board — factor this into the enclosure depth if the mating connector has a backshell.