A small 41.5 KB PDF for the 2SD1458, a part number in the Japanese JIS scheme where 2SD identifies an NPN low-frequency transistor. The file is catalogued as a schematic, but a name like this normally belongs to a component datasheet. The _E suffix is part of the original name, and its meaning is not stated. Use it to check the pin order, collector-emitter rating, gain class and case outline before ordering a substitute. Compare the package and marking on the board with the drawing before relying on any figure.
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.