A 64 KB PDF covering the 2N7218, indexed as a schematic though the file name is a plain JEDEC part number and the content is most likely a single-device datasheet. No manufacturer, package suffix or revision appears in the name. Repair technicians consult sheets like this to identify pins, read safe operating limits and characteristic curves, and pick a suitable substitute. Verify the outline drawing against the actual component and its markings, since datasheets from different makers of the same number may vary slightly.
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.