PDF of 60.0 KB named 2SC5127, categorized as a schematic though it should be the device datasheet for that NPN bipolar transistor. JIS part numbers starting with 2SC denote NPN transistors of the high-frequency class. The name gives no further details. Datasheets like this list absolute maximum ratings, electrical characteristics and the outline drawing, useful when identifying leads, testing with a meter and choosing a replacement with equal or better ratings. Check the original component marking before relying on it.
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.