The part number 2SK2327 is the only information in the name of this 32.8 KB PDF, filed as a schematic. Since 2SK is the Japanese JIS designation for N-channel field-effect transistors, it is best treated as a datasheet. Use it to read electrical characteristics, safe operating limits and pin assignment when testing the transistor with a meter or seeking an equivalent for a power stage. Any PDF reader will open it; check that the device marking and package agree with the document first.
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.