Named only for the 2SK2074, this 95 KB PDF is catalogued as a schematic but is most likely the transistor's datasheet. Under the Japanese JIS scheme the 2SK prefix identifies an N-channel field-effect transistor. No maker or package is stated. The sheet supports routine repair checks: identifying pins for in-circuit or bench testing, reading absolute maximum ratings, and comparing on-resistance and gate threshold with any candidate replacement before soldering it in.
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.