At 130 KB, this PDF documents the 2SD1060, the largest of its neighbouring files and filed as a schematic. Nothing beyond the part number appears in the name. Following JIS numbering, 2SD marks an NPN low-frequency bipolar transistor, so the content will typically cover electrical ratings, pin configuration and performance graphs. A technician consults it to identify leads before testing with a meter in diode mode and to evaluate whether a proposed replacement handles the circuit's voltage and dissipation.
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.