DF40HC(4.0)-80DS-0.4V(58) from Hirose Electric Co Ltd is a fine-pitch rectangular mezzanine connector designed for compact board-to-board interconnect applications where space, signal density, and assembly consistency matter. As part of the DF40 series, this 80-position, 0.40 mm pitch receptacle is well suited for portable electronics, industrial control boards, embedded modules, communication devices, and other multilayer PCB designs that require a 4 mm mated stacking height. Its surface-mount format and tape-and-reel packaging support automated production, while gold contact finish helps support reliable contact performance in high-density assemblies. The provided product data lists this part as Active, which is generally favorable for ongoing designs, although lifecycle should still be verified through current manufacturer documentation. RoHS compliance information is not explicitly provided in the supplied specifications, so compliance status is information not available from this dataset. Engineers should confirm RoHS and any REACH requirements directly with Hirose or the latest official datasheet before release to production.