2SJ194 is the sole identifier in this 117 KB PDF; in JIS designations the 2SJ series covers P-channel field-effect transistors, so the document should be a part datasheet despite its schematic category. Repair use centres on confirming gate, drain and source positions, polarity and maximum ratings when testing or substituting the device. Any viewer such as a standard PDF reader opens it. Verify the manufacturer marking and package of the original part, as the file name states neither.
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.