Indexed as a schematic, this 422 KB PDF is titled 2SK2201 and most likely contains the datasheet for that part. The 2SK prefix places it among N-channel field-effect transistors in the Japanese JIS/EIAJ system, while maker and package are not stated. Use the document to verify pin assignment, maximum drain voltage, drain current and on-resistance. Choose a replacement only if it matches or exceeds these. Any PDF viewer opens the file without special software.
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.