Indexed as a schematic, this 95.8 KB PDF carries only the designation 2SC4821. In the JIS system the 2SC prefix denotes an NPN transistor, so the content is most likely that part's datasheet; no brand, case style or ratings appear in the name. Repair technicians use such documents to verify pinout before in-circuit measurement, look up maximum ratings and pick an equivalent with equal or better limits. Open it in any PDF reader and match the code on the actual component before ordering.
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.