Document for the 2SD869 transistor, catalogued as a schematic though the name only gives a part number, so it is most likely the datasheet. The 2SD prefix marks an NPN bipolar device. The 194 KB PDF should list collector-emitter and collector-base voltages, current, dissipation and package details. Technicians check it before replacing a shorted transistor, confirming lead order and choosing an equivalent that fits the same footprint and heatsink and handles the same voltage.
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.