DF40GB(1.5)-48DS-0.4V(51) from Hirose Electric Co Ltd is a fine-pitch rectangular board-to-board mezzanine receptacle designed for compact electronic assemblies where space, signal integrity, and reliable mating performance matter. As part of the DF40 series, it is well suited to portable devices, industrial control boards, embedded modules, communication equipment, and other high-density PCB stacking applications that benefit from a 0.40 mm pitch and 1.5 mm mated stacking height. Features such as shielding and solder retention support design robustness in tightly integrated layouts. For procurement teams and design engineers, this part is positioned as a precision interconnect for miniaturized systems that require reputable manufacturer backing and tape-and-reel packaging for automated assembly. Lifecycle status is currently listed as unknown, so long-term programs should verify supply continuity directly with Hirose or authorized channels. RoHS compliance information is not explicitly provided in the supplied specifications, so engineers should confirm current RoHS and REACH status through official manufacturer documentation before release to production.