15-position, 4.20 mm pitch, 3-row latch-lock header
This 640503-1 is a 15-position, 3-row header on a 4.20 mm pitch — the row spacing matches the pitch at 0.165" (4.20 mm), so the footprint is a uniform grid that simplifies PCB layout. The latch lock fastening holds the mating receptacle against vibration and cable tug, which matters for equipment that sees movement or shock.
