A 40.6 KB PDF for the component 5HN02C. Although classed as a schematic, the file name contains just a part code, with C probably denoting the package, and states no device or board. A datasheet of this kind lists pinout, electrical limits and typical performance curves. Technicians use it when a small transistor near a fault is suspected, checking polarity and ratings before replacement. Match the suffix and footprint to the original part, since series variants can differ in size.
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.