A small 26.9 KB PDF in the schematic category, named only with the part number 2N6519 from the JEDEC 2N registration series. No board, revision or device is mentioned, and files with this naming are typically single-part datasheets. Inside you would look for the lead assignment, package outline and absolute maximum ratings needed to identify a component, confirm a cross-reference or test it out of circuit with a multimeter. Any PDF reader will display it; check the printed marking on the physical part 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.