The 2SC4071 is the subject of this 47.7 KB PDF, which sits in the schematic category although the name suggests a single-component datasheet. Under JIS rules the 2SC prefix denotes an NPN bipolar transistor. Beyond that, the name tells nothing about manufacturer or case. Datasheets of this kind supply the pinout, limits and characteristic graphs needed to test a transistor in or out of circuit and to choose a safe replacement. Check the actual part marking first, because similar numbers belong to very different devices.
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.