Named only 2SC4213, this 289 KB PDF is catalogued as a schematic, yet the JEITA-style 2SC prefix identifies an NPN bipolar transistor, so a component datasheet is the realistic expectation. It should list maximum ratings, electrical characteristics and the package outline. The name gives no maker or variant suffix. Before replacing a part, check the marking on the original, confirm that the pin arrangement in the drawing matches the PCB footprint, and compare gain and voltage figures with any proposed substitute.
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.