A 121 KB PDF named in lowercase after the 2SC3969 transistor and placed in the schematic section, though its content is most likely a part datasheet. In JIS numbering, the 2SC series covers NPN bipolar transistors. The sheet serves as the reference for pinout, absolute maximum ratings, hFE and package dimensions when a technician tests or replaces the device. The name says nothing else, so verify that the C3969 code printed on the component and its case style match before using the data.
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.