The FCI 87901-438HLF is a 38-position, dual-row unshrouded header from the BERGSTIK® II series, built for board-to-board stacking applications on a standard 0.100" (2.54 mm) pitch.
What the 38 positions and 0.100" pitch mean for your board
38 positions on a 2-row layout means 19 pins per row, spanning about 1.8 inches of board edge. The 0.100" (2.54 mm) pitch matches the standard DIP IC footprint — your PCB layout can use a conventional through-hole pattern with 0.100" row spacing. The overall contact length is 1.040" (26.42 mm), with a mating length of 0.820" (20.83 mm) and a post length of 0.120" (3.05 mm) — the post length determines how far the pin protrudes through the board for soldering.
Tin-plated contacts are cost-effective for one-and-done or low-cycle-count interconnects — think a permanent board-to-board stack where the header gets mated once during assembly and stays put.
This is a standard BERGSTIK II catalog part, so it's a safe BOM line for production builds. No official cross-reference or direct substitute is on record — if you need an alternative, look at other 38-position, 0.100" pitch unshrouded headers in the same series with the same post length.