Sizing the Board-to-Board Stack for 55510-018LF
The 55510-018LF is a Minitek® 2.00mm series receptacle, 18 positions in two rows at 0.079" (2.00mm) pitch — the footprint matches a standard 2.00mm header, and the row spacing is also 2.00mm, so the board-to-board stack height is set by the header's mating post length.
Surface mount termination with tin-plated posts suits reflow soldering; the insulation height of 0.177" (4.50mm) gives clearance for the solder joint and the mating header's shroud.
RoHS compliance is standard for the LF suffix; the part carries no additional environmental restrictions beyond the base series.