The 2SK2750 is covered by this 394 KB PDF, indexed as a schematic but most likely the component datasheet, since 2SK is the JIS prefix for N-channel FETs. The larger size suggests a fuller document with characteristic curves and package drawings. A technician would rely on it when matching a substitute by voltage, current, on-resistance and gate charge, or when confirming which leg is the gate before in-circuit measurements. No manufacturer or version is stated in the name, so compare markings on the part itself.
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.