The 2SA1123 PNP transistor is the subject of this 40.5 KB PDF, whose name carries an _E suffix. Filed under schematics, it should actually hold datasheet material: maximum collector voltage and current, power dissipation, gain classes and an outline drawing. The 2SA prefix comes from the JIS standard for PNP devices. Use it to verify pin order before soldering, to cross-reference a substitute part, and to interpret the gain-rank letter that may be stamped on the original component.
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.