For the 2SK614, a part number from the JIS family of N-channel field-effect transistors, this 32.7 KB PDF is catalogued as a schematic but is most plausibly a short component datasheet. The name gives no maker or package details. It is handy for reading pin assignments, absolute maximum ratings and typical characteristics, testing a suspect transistor out of circuit, and comparing specifications when choosing a cross-reference part. Any regular PDF reader opens it, and printing a copy for the bench is easy.
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.