What This Connector Is — DF12 Series Mezzanine Header
The DF12(4.0)50DP0.5V(80: This is a Hirose DF12 series board-to-board mezzanine header, 50 positions in a dual-row arrangement at 0.020" (0.50 mm) pitch. The connector type is Header, Outer Shroud Contacts — meaning the mating interface uses shrouded contacts that surround the receptacle's pins, providing alignment and protection during mating.
The surface-mount termination and 0.50 mm pitch demand a precise PCB footprint; the Board Guide aids optical alignment during pick-and-place. The Solder Retention feature provides additional mechanical hold on the board after reflow, important for a 50-position connector that sees insertion forces from the mating half.