DF37C-30DP-0.4V(51) from Hirose Electric Co Ltd is a fine-pitch rectangular board-to-board connector designed for compact electronic assemblies where low profile, reliable mating, and dense interconnects are important. As part of the DF37 series, this 30-position, 0.40 mm pitch surface-mount header is well suited for portable devices, industrial control modules, display assemblies, embedded systems, and other space-constrained PCB designs that require mezzanine-style board stacking. Engineers typically choose parts in this category for signal routing between stacked boards while maintaining mechanical stability and compact product dimensions. The listed product status is Active, which is a positive indicator for ongoing design use, although lifecycle planning should still include manufacturer verification and approved alternates. RoHS compliance information is not explicitly provided in the supplied specifications, so compliance status should be treated as information not available until confirmed through the official datasheet, manufacturer declaration, or distributor documentation.