The 2SK2350 is identified here only by its part number, in a 417 KB PDF catalogued as a schematic. The 2SK prefix in the Japanese JIS scheme marks an N-channel FET, so expect a component datasheet with ratings, characteristic curves and package drawing rather than a circuit diagram. It helps when matching a failed transistor in a power supply or driver stage to an equivalent part. Confirm the full marking on the device body, including any suffix letters, before relying on the figures.
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.