Small 57.3 KB PDF for the 2SC5060, filed under schematics though the name suggests a transistor part sheet. Japanese JIS numbering marks 2SC devices as NPN transistors aimed at high-frequency use, so the document should list pinout, package, maximum ratings and gain figures. Technicians consult it to identify the base, collector and emitter pins, check junctions with a meter and find an equivalent with matching voltage, current and frequency ratings. Compare the printed marking and package on the component before relying on the data.
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.