The FCI BERGSTIK® II 86837-440HLF is a 40-position, dual-row, unshrouded male header on a standard 0.100" (2.54 mm) pitch.
The 0.100" pitch and 0.100" row spacing define the PCB footprint — a 40-pin dual-row layout needs 20 holes per row at 2.54 mm pitch, with a 2.54 mm gap between rows. The 0.120" solder tail length suits standard 1.6 mm boards.
The 100.0 µ" tin-on-tin mating finish is thick enough for moderate mating cycles — think prototype rework or infrequent board swaps — but the tin surface will wear with repeated insertion.