At 188 KB, this PDF for the 2SC5466 is larger than a basic sheet and likely includes full characteristic curves and package drawings. The 2SC prefix identifies an NPN bipolar transistor under Japanese JIS numbering, so despite the schematic label it is best treated as a datasheet. Technicians rely on it for breakdown voltage, collector current, dissipation and pin assignment. Compare these figures with any substitute and confirm the body marking on the board before replacing the 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.