PDF of 98.9 KB for the 2SK1898, listed under schematics but in practice a component reference for one transistor. Japanese JIS codes beginning 2SK identify N-channel field-effect transistors. A repair technician reads such a datasheet for the gate, drain and source layout, maximum ratings and package dimensions when a FET fails short or open. Since the name gives only the part number, compare the logo and marking on the device with the document before using the figures.
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.