A 116 KB PDF for the 2SK2731 bearing a 1-5 suffix that the name does not explain, perhaps an edition marker. The same part also appears under a plain file name, so the two can be compared. As 2SK denotes an N-channel FET in JIS numbering, this is essentially a datasheet with ratings, electrical characteristics and package information rather than a circuit drawing. Use it to verify pinout, voltage and current limits and to select a compatible substitute when replacing a failed transistor.
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.