The 63453-044LF: It mates with matching 2.00mm pitch pin headers to create a stack height determined by the header's post length.
The 0.079" pitch drives the board footprint: 44 holes in two rows, each row spaced 0.079" apart. When mated with a header, the total stack height is the sum of the receptacle height and the header post length above the board.
Contact Plating and Mating Interface
The square contact shape mates with square or round header pins of matching pitch.