DF36-40P-0.4SD(51) from Hirose Electric Co Ltd is a 40-position rectangular plug in the DF36 series, designed for compact wire-to-board interconnect applications where fine pitch and reliable mechanical retention are important. With a 0.40 mm pitch, free-hanging in-line mounting style, latch holder fastening, and solder cable termination for 42-46 AWG discrete wire, it is well suited for dense consumer, portable, embedded, and miniaturized industrial electronic assemblies. Engineers typically select this type of connector when balancing space savings, secure mating, and assembly consistency in tightly packed systems. The listed product status is Active, which supports ongoing design consideration, although teams should still monitor supply conditions and confirm long-term availability directly with authorized sources. RoHS compliance information is not explicitly provided in the supplied specifications, so compliance status should be treated as information not available until verified through the manufacturer datasheet or formal compliance documentation.