51-Position Board-to-Board Receptacle at 1.00mm Pitch
The 0.039" (1.00mm) pitch and dual-row layout pack 51 circuits into a compact footprint, with a mated stacking height of 4.3mm that sets the board-to-board gap.
The DF9-51S-1V(69) carries 51 positions. The DF9-41S-1V(69) is the 41-position version at the same 0.039" (1.00mm) pitch, same 4.3mm stacking height, and same gold contact finish — the only difference is circuit count. If the BOM calls for 41 circuits, the 41-position variant is a direct footprint match; if the design needs 51, this is the one. No other specs change between the two.