PDF reference, 115 KB, for the 2SK1924 N-channel field-effect transistor; the 2SK prefix places it in the Japanese JIS transistor registry. Despite the schematic label, expect datasheet content: pinout, package outline, electrical characteristics and limits. It is handy when a FET in a power or switching circuit is suspected and you need to test the right legs or choose a replacement with matching ratings. The name states only the part number, so confirm package and suffix on the real device.
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.