Catalogued as a schematic, this 149 KB PDF is labelled just 2SC3416, a JIS designation in which 2SC marks an NPN bipolar transistor. Expect a datasheet rather than a circuit diagram. Technicians consult such sheets to identify leads for in-circuit testing, to verify maximum ratings and to judge whether a substitute part is suitable. Any PDF reader will open it. As the name lacks package, maker and gain-rank details, check the code printed on the component, usually C3416.
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.