What this is
The JST B3P-VH(LF)(SN) is the 3-circuit member of the VH series — a single-row, 3.96 mm pitch board-to-cable header with a 1-wall shroud and locking ramp. The locking ramp adds positive retention over a plain friction-fit header, which matters in any harness that sees vibration or repeated mate/de-mate cycles in the field. Brass contacts are tin-plated across both the mating interface and the solder tail, rated 10 A per circuit at 250 V. The insulator is PA66 nylon rated UL94 V-0, which is the flame-class floor for enclosed equipment — it will not support combustion but it is not a sealed connector. Mated stack height is 16.5 mm and the overall contact length is 0.575 in (14.60 mm) with a 0.146 in (3.70 mm) solder-tail reach.
Where the class is used
VH headers are common in power-supply board assemblies, industrial-control modules, and white-goods control boards — anywhere a compact, non-keyed header carries moderate current to a wire harness. The shroud adds mechanical protection to the contact row during handling and assembly, which matters on production lines where exposed contacts bend. The 1-wall shroud leaves one side open for visual pin inspection and for the wire-entry geometry of the matching housing.