Reference sheet for the 2SK1109, with the name indicating the UTC (Unisonic Technologies) version of the part. Listed under schematics, the compact 10.3 KB PDF is in practice a component datasheet for an N-channel field-effect transistor from the 2SK series. Repair technicians consult it for pin assignment, package outline and electrical limits when testing or replacing the device. Any PDF viewer opens it. Different makers may vary ratings slightly, so compare the UTC figures with the original part fitted on the board.
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.