The 0.820" (20.83 mm) mating pin length provides good wipe depth for reliable contact with standard receptacles, while the 0.120" (3.05 mm) post length suits typical board thicknesses.
The 52-position 87901-452HLF sits alongside the 50-position 87901-451HLF in the same BergStik II family. Select the 52-position variant when the BOM calls for 52 circuits; the 50-position version covers a 50-circuit requirement. No other functional specs differ between the two.
It is RoHS compliant per current documentation.
