Catalogued among schematics, the 43.5 KB PDF called 2SJ499's neighbour 2SJ485 refers to a semiconductor part; under the JIS scheme the 2SJ prefix designates a P-channel field-effect transistor. The small file is likely a concise datasheet listing ratings, characteristics and pinout. Technicians open it to verify gate, drain and source positions, confirm voltage and current limits, and evaluate possible substitutes when the original has failed. The name states no device or package, so check the marking on the board before swapping.
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.