A 272 KB PDF for part number 2N5555, with a rev0x tag in the name that seems to mark a document revision, though its exact meaning is not stated. It sits in the schematic category, but the JEDEC 2N code points to a discrete component datasheet. No board or device is mentioned. Use it to read pinout, case style and electrical limits when identifying or substituting the part. Compare the marking on the component and, if possible, another revision of the sheet before relying on borderline values.
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.