It uses a 6.71 mm pitch and 6.71 mm row spacing across three rows, which gives each circuit enough physical separation for the rated voltage and current without requiring an oversized connector body. The housing accepts either male or female contacts (sold separately), terminated via crimp. Mating is with the corresponding 3191 series pin header (male pin housing) of the same 12-circuit, 3-row, 6.71 mm pitch layout.
The 0019091129 mates with a 3191 series male pin header (receptacle counterpart) of identical 12-position, 3-row, 6.71 mm pitch. The housing accepts both contact genders, so the same shell can serve as either the plug or receptacle side depending on which terminal is loaded.