The 3.81mm pitch and 5.08mm row spacing give it a 4-row layout that carries 20 circuits in a compact footprint — the row count matters because it determines the header width and the board space the mating pin header occupies.
The 20 positions are the first check against the BOM line — count the circuits on the mating header and confirm it matches. The 3.81mm pitch is wider than the 2.00mm or 2.50mm found in compact signal connectors; that extra spacing gives more creepage for higher-voltage applications and makes the crimp terminals easier to handle with standard tooling. The 4-row arrangement means the mating header will have four rows of pins — the board footprint must accommodate that row count and the 5.08mm row spacing.
This receptacle mates with the corresponding Dynamic D-3400 series pin header — the header will have 20 pins in a 4-row arrangement at the same 3.81mm pitch. The crimp termination accepts the Dynamic D-3400 female socket contacts (sold separately); the wire range and crimp die selection follow the terminal datasheet. The free-hanging housing has no board locks or mounting ears, so the harness relies on the primary latch of the mating header for retention.