PDF datasheet of 137 KB for the 2SK3120, sorted into the schematic category of the index. Under the Japanese JEITA numbering, the 2SK prefix denotes an N-channel field-effect transistor. A repair technician reads this kind of document to confirm which terminal is which, check breakdown voltage, drain current and on-resistance, and compare the package with the board footprint. The name holds nothing beyond the part number, so verify all specifics within the document 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.