Short PDF of 50.8 KB for the 2SC1509, with an _E suffix in the file name, listed in the schematic section. The 2SC designation belongs to the JIS scheme for NPN bipolar transistors, so this is probably the device datasheet with pinout, package outline, ratings and characteristics. Use it when checking the transistor with a meter, confirming lead order before removal or comparing replacements. Because no manufacturer is stated, match the marking and case style of the board component with the document first.
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.