DF40C(2.0)-24DS-0.4V(51) from Hirose Electric Co Ltd is a fine-pitch board-to-board rectangular connector designed for compact electronic assemblies where space, stacking height, and signal density matter. As part of the DF40 series, this 24-position, 0.40 mm pitch receptacle is well suited for portable devices, industrial control modules, communication equipment, embedded systems, and other high-density PCB interconnect designs. Engineers typically select this type of connector when they need reliable mezzanine mating in low-profile layouts and surface-mount assembly processes. The listed product status is Active, which supports consideration for ongoing designs, although procurement teams should still monitor lead times and long-term availability. RoHS compliance information is not explicitly provided in the supplied specifications, so compliance should be treated as information not available pending confirmation from the official Hirose datasheet or manufacturer declaration. For regulated products, engineers should also verify REACH status and any material disclosures before release to production.