Datasheet for the 2SJ412 P-channel field-effect transistor, provided as a 328 KB PDF; the larger size suggests detailed curves and package drawings. The 2SJ prefix belongs to the Japanese JIS discrete semiconductor numbering scheme. The file name states only the part number, with no maker or variant. Technicians use such a sheet to identify terminals, check breakdown voltage and drain current, and evaluate replacements, always confirming that the package and pin order match what is fitted on the PCB.
The button opens the matching file on RM Schematics, or a source page if it is not catalogued there yet. The original attachment is from @cyberlanelectonik. Enginerys does not host this file.
How to open a .pdf file
The standard format for schematics, block diagrams, power-sequence charts and service manuals.