The Amphenol FCI 87052-166HLF is a 66-circuit unshrouded male header from the BERGSTIK II series, built on the standard 0.100" (2.54 mm) pitch in a dual-row layout. The 66 positions are fully loaded, so every pin is present for the full circuit count.
The 0.100" pitch and 0.100" row spacing are the classic 0.100" x 0.100" grid — a standard footprint that matches decades of legacy board layouts and common receptacle families. The 0.770" (19.56 mm) mating pin length gives good wipe before the contact beams engage, and the 0.120" (3.05 mm) solder post is sized for a standard 0.062" PCB with through-hole soldering. The 66-position count is the defining BOM line match — at 33 per row, it is a dense but manageable footprint for a multi-conductor board-to-board link. The unshrouded profile means the board layout must account for the exposed pins; there is no shroud to prevent a misaligned mate, so the mating receptacle needs its own alignment features or the assembly fixture handles registration.