A 155 KB PDF for the 2SC5245 transistor, catalogued as a schematic but by its name almost certainly a component datasheet. Parts carrying the 2SC prefix are NPN bipolar transistors under the JIS EIAJ registration scheme. Repair technicians open such sheets in any PDF reader to check collector-emitter voltage, gain grouping, package and pin order when sourcing a substitute. Confirm the marking on the failed device first, because SMD codes are often abbreviated and can be mistaken for unrelated parts.
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.