A 144 KB PDF whose name is just the part number 2SD1190, filed as a schematic but in practice a transistor datasheet. Japanese JIS numbering uses the 2SD prefix for NPN bipolar transistors aimed at low-frequency applications. Open it in any PDF viewer to look up the pinout, gain classification and limiting values. These details matter when testing a suspect part in circuit or picking a replacement, because similar-looking packages from different makers can differ in lead order.
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.