For the 2SC5450 there is a 41.0 KB PDF, filed as a schematic, most likely holding the datasheet of this NPN transistor from the Japanese 2SC family. Expect pin assignment, package dimensions, ratings and electrical characteristics. It is helpful when a transistor has failed and its exact specification must be matched. Confirm the code printed on the part, check the package so the footprint fits, and compare breakdown voltage and current with any alternative before installation.
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.