DF40C-60DP-0.4V(51) from Hirose Electric Co Ltd is a fine-pitch rectangular board-to-board connector designed for compact electronic assemblies that need reliable high-density interconnection in a low-profile format. With 60 positions, 0.40 mm pitch, SMT mounting, and multiple supported mated stacking heights, it is well suited for portable devices, industrial control modules, embedded computing platforms, medical electronics, and other space-constrained designs where mechanical precision and signal routing density matter. Engineers often select this series for compact PCB stacking, dependable mating performance, and assembly-friendly features such as solder retention and gold contact finish. Based on the provided product data, the part status is Active, which is favorable for ongoing procurement, although the broader lifecycle field is listed as unknown and should still be verified with Hirose for new long-term programs. RoHS compliance information is not available in the provided specifications, so designers should confirm RoHS and related material declarations through the official datasheet or manufacturer documentation before release to production.