The FCI 86503-438HLF is a 38-position, dual-row unshrouded header from the BERGSTIK® II series, designed for board-to-board interconnect on a standard 0.100" (2.54mm) pitch grid.
The 0.100" pitch and row spacing are the classic 2.54mm grid — any standard 0.100" female socket strip or IDC receptacle will align. The overall contact length of 0.470" breaks down to a 0.250" mating section and a 0.120" post length, which sets the board-to-board stack height and the through-hole depth on the PCB.
Where it fits — board-to-board duty
This is a board-to-board header, period — it sits on one PCB and mates with a female socket on another. Typical use is in card-edge or mezzanine stacking where the two boards are parallel and the header provides the signal path. The 38-pin count suits parallel data buses, I/O expansion headers, or general-purpose interconnect on a prototype or production board where the pinout is defined by the circuit count.