The YL series is a standard power connector family — the 4.50mm pitch gives enough creepage for moderate-voltage circuits without the bulk of a larger industrial connector.
The 12 circuits in a dual-row arrangement mean the housing occupies about 27 mm across the width — a compact footprint for a 12-way power connector. The 4.50mm pitch is wider than typical signal connectors (2.54mm or 1.25mm), which means the crimp terminals can carry higher current without thermal crowding between adjacent contacts. Against the 6-position YLP-06V, this part doubles the circuit count in the same row pitch; against the 16-position YLP-16V(NN), it saves four positions when the BOM calls for exactly 12 circuits. The latch lock is the same across all three, so the mating receptacle housing and terminal are shared within the series.