DF40C-34DP-0.4V(51) from Hirose Electric Co Ltd is a rectangular board-to-board mezzanine connector used where compact interconnect density and reliable PCB stacking are important. In applications such as portable electronics, embedded control boards, industrial modules, and communication devices, this type of connector helps engineers route signals between tightly spaced boards while supporting streamlined assembly through tape-and-reel packaging. Based on the provided data, the product status is Active, which is a positive indicator for ongoing design consideration, although lifecycle should still be confirmed directly with Hirose for long-term programs. RoHS compliance information is not explicitly provided in the supplied specifications, so compliance status should be treated as information not available until verified through official manufacturer documentation. With MSL 1 handling data and standard packaging of 5,000 pieces, this part is positioned for volume manufacturing, prototype-to-production transitions, and procurement teams seeking a currently active Hirose interconnect option.