DF36-20P-0.4SD(51) from Hirose Electric Co Ltd is a DF36 series rectangular plug connector designed for compact interconnect applications where fine-pitch, high-density cable termination is important. Based on the provided specifications, it is a 20-position plug with solder termination, gold contact finish, and support for 42–46 AWG conductors, making it suitable for space-constrained consumer, portable, industrial, and embedded electronics assemblies. As part of the Connectors, Interconnects > Rectangular Connectors category, it fits design needs that prioritize signal integrity, miniaturization, and reliable board-to-cable or in-line connection performance. Lifecycle status is currently listed as unknown, so engineering and procurement teams should verify ongoing manufacturer support before committing to long production programs. RoHS compliance information is not available in the supplied data, so compliance should be confirmed directly through the official Hirose datasheet, declaration, or manufacturer documentation before use in regulated markets.