A 52.2 KB PDF in the schematic listing, labelled simply 2N6487, a part number from the JEDEC 2N discrete semiconductor series. With no board or device stated, the file should be a short datasheet covering pin assignment, package outline and absolute maximum ratings. It is handy when identifying a component on a power or driver stage, testing it out of circuit, or finding a cross-reference part. Open it in any PDF reader and compare with the RE-marked edition if you need more detailed curves.
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.