What this connector is
The Amphenol FCI 57102-G06-21ULF is the 42-position member of the Minitek® 2.00mm board-to-board header series — a dual-row, unshrouded male pin header with 2.00mm pitch and through-hole termination. The dual-plating strategy places gold GXT™ (30.0µin / 0.76µm) on the mating interface and tin (78.7µin / 2.00µm) on the solder post side, so the high-cycle face gets the wear-resistant finish while the post side optimises for solderability. Push-pull fastening holds the mated pair — adequate for board stacking in stable environments, though vibration-heavy applications typically want a shrouded or screw-locked alternative within the same series.
Ratings that drive the fit decision
The gold GXT™ plating on the mating face (0.76µm) is the meaningful selection lever — it provides the wear resistance and low contact resistance for repeated mating cycles, which is where this header earns its place over a tin-only part. The tin post plating at 2.00µm is a standard solder-tail finish; it meets the wetting requirements for through-hole reflow or hand-solder assembly without special process consideration.