DF40HC(3.0)-60DS-0.4V(51) from Hirose Electric Co Ltd is a fine-pitch rectangular mezzanine connector designed for compact board-to-board interconnection in space-constrained electronic systems. As a 60-position, 0.40 mm pitch receptacle in the DF40 series, it is well suited for portable devices, industrial control modules, embedded computing platforms, medical electronics, and other designs that require reliable high-density stacking between PCBs. Its SMT mounting style, tape-and-reel packaging, and 3 mm mating stack height support automated assembly and low-profile product architectures. For design teams, this part offers value in applications where signal density, board space, and assembly efficiency must be balanced carefully. Lifecycle status is listed as unknown, so engineers should verify current manufacturer status before locking it into new designs or long-term production builds. RoHS compliance information is not available in the provided specifications, so environmental compliance should be confirmed through the official datasheet, manufacturer declarations, or authorized sourcing channels.