The 2SJ225 is the only information this 91.8 KB PDF name provides; the 2SJ prefix in Japanese semiconductor numbering identifies a P-channel field-effect transistor. Despite the schematic label, the document is presumably a datasheet for that device. It is handy when testing a suspect transistor out of circuit, checking which pin is gate, drain and source, or comparing ratings with an available equivalent. Open it in any PDF viewer and confirm the package and marking on the board match before relying on the figures.
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.