A 117 KB PDF bearing the part number 2SC4860 and nothing else, indexed as a schematic. Since the JIS/JEITA scheme assigns the 2SC prefix to NPN bipolar transistors, the document is best treated as a component datasheet. Expect tables of ratings and characteristics together with a package outline. Use it to check which pin is base, collector and emitter, to confirm voltage and current limits suit the circuit, and to verify that a replacement shares the same footprint before soldering.
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.