The FCI 86837-426HLF is a 26-position, dual-row unshrouded header from the BergStik® II series, built for board-to-board interconnect on a standard 0.100" (2.54 mm) pitch.
Tin does not handle repeated insertion as well as gold — if this header sees frequent reconnection in a corrosive or high-humidity setting, the contact resistance will drift over time. For a one-time board-to-board stack inside a sealed chassis, tin is fine. In a high-vibration environment, the header can walk out of the receptacle over time.
Phosphor bronze contact material with tin plating — the bronze spring properties hold contact force over temperature, and the tin wets well during wave solder. The overall contact length is 0.600" (15.24 mm), with a 0.380" (9.65 mm) mating length and a 0.120" (3.05 mm) solder post.