The Hirose DF12A(3.0)-30DS-0.5V(81) is a 30-position receptacle with center strip contacts from the DF12 series, designed for board-to-board mezzanine stacking at a 3mm mated height.
Board Layout Fit — Pitch, Stack Height, and the Board Guide
At 0.50mm pitch, the footprint for this receptacle demands a PCB fab capable of fine-line routing between pads — standard 0.5mm-pitch land patterns with 0.25mm to 0.30mm pad width. For a technician mating these by hand, the guide prevents the kind of off-angle push that bends a 0.50mm-pitch contact — worth having on the assembly line.