Component PDF for the 2SA1248, 47.6 KB, which the index lists as a schematic. Only the part code appears in the name; under the JIS system, 2SA designates a PNP transistor, so this is most likely its datasheet. It should contain pin assignments, package information, maximum ratings and characteristic values. Use it to verify orientation before soldering, to read gain classification markings, and to check that any cross-referenced equivalent meets or exceeds the original voltage and current specifications.
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.