DF37B-34DP-0.4V(75) from Hirose Electric Co Ltd is a fine-pitch rectangular board-to-board connector designed for compact electronic assemblies where space, signal density, and assembly reliability matter. As a 34-position, 0.40 mm pitch SMT header with gold-plated contacts, outer shroud contacts, and solder retention features, it fits applications such as mobile devices, industrial control modules, embedded systems, portable instrumentation, and other densely packed PCB designs. Engineers typically choose this series when low-profile stacking and stable board interconnection are required in space-constrained layouts. Based on the provided product data, the part is listed as Active, which supports use in ongoing production, although lifecycle verification with Hirose or the latest datasheet is still recommended. RoHS compliance information is not explicitly provided in the supplied specifications, so compliance status should be treated as information not available pending official manufacturer documentation. For procurement teams, current supply is indicated as sufficient, which may help reduce sourcing pressure for active designs.