The 2SK1925 is the subject of this 115 KB PDF, a datasheet for an N-channel FET as identified by the 2SK prefix of the JIS scheme, though the index lists it under schematics. Technicians open it to check the pin order before diode-mode testing, read absolute maximum ratings and compare characteristics when looking for an equivalent. No manufacturer or package is given in the file name, so check that the printed code on the component matches this sheet before trusting it.
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.