PDF datasheet covering the 2SA1815, a part whose 2SA prefix identifies it under the JIS scheme as a PNP bipolar transistor. The file is 70.3 KB and is indexed as a schematic, though its content is component reference data rather than a circuit diagram. Technicians open it in any PDF reader to confirm collector-emitter voltage, current limits, gain grouping and pin order. Use those figures when choosing a substitute, and verify the package type before soldering in a replacement.
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.