PDF document of 299 KB named for the 2SK117, most likely a datasheet even though the catalogue lists it as a schematic. JIS numbering assigns the 2SK prefix to N-channel field-effect transistors. Any PDF reader opens it; the key data for a technician are the gate, drain and source pins, package drawing, ratings and any grade classification. When replacing the part, match the rank suffix on the original where present and confirm the footprint so the pin order on the board is respected.
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.