Manufacturer datasheet for the 2SK3569, a discrete transistor part number in the Japanese 2SK series, which denotes N-channel field-effect devices. The PDF normally lists absolute maximum ratings, electrical characteristics, package outline and pin assignment. Technicians consult it when a power supply or inverter stage has a failed MOSFET and a direct or equivalent replacement is needed, comparing drain-source voltage, current rating, on-resistance and gate threshold before fitting a substitute part 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.