The Amphenol FCI 91276-127HLF is a 27-position unshrouded male pin header from the BergStik II series, designed for board-to-board interconnect on a standard 0.100" (2.54 mm) pitch. It is a single-row, through-hole solder part with a push-pull fastening system — no latch, no shroud, just the pins and the insulator. The 0.900" (22.86 mm) mating pin length gives it reach through stacked boards or into a shrouded receptacle.
The 0.100" pitch fits standard perfboard and prototype boards. This saves board space and cost, but the mating half must provide its own alignment. In a high-vibration environment, the push-pull retention relies entirely on the contact friction fit; a locking receptacle or a dab of thread-locker on the header pins is common field practice.