Datasheet document, by all indications, for the 2SJ189, a JIS-registered P-channel FET, held as an 83.5 KB PDF in the schematic section. It typically lists maximum ratings, electrical characteristics and a package drawing. In repair it helps when measuring a suspect transistor, confirming polarity and choosing an equivalent with matching pinout and adequate ratings. The name is limited to the part number, with no maker or case style, so verify those details on the original device first.
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.