The Hirose DF30FC-24DS-0.4V(82) is a 24-position receptacle from the DF30 series, designed for board-to-board mezzanine stacking in compact portable electronics.
The receptacle itself sits 0.88mm above the board surface, so the total stack from bottom PCB to top PCB is that 0.9mm mated height, not the sum of both heights.
Comparing the 24-Position to the 20-Position Sibling
The DF30FC-24DS-0.4V(82) carries 24 positions against the 20 positions of the DF30FC-20DS-0.4V(82) at the same 0.40mm pitch and 0.9mm mated height. The extra four circuits increase the signal density across the same board footprint width — the connector body is longer to accommodate the additional contacts, so verify the mechanical envelope against your PCB edge clearance if you're swapping between position counts.
