A 255 KB PDF for the 2N4918, tagged RE in the name, possibly a revised or alternate edition though this is not defined. Listed under schematics, it is best treated as the component datasheet for that JEDEC part. At the bench it helps with identifying leads, checking voltage, current and dissipation limits and comparing equivalents. Open it in a standard PDF reader, and confirm that the case style and pin arrangement match the device on the board before replacing 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.