PDF of 242 KB covering the 2N6040, classified as a schematic but almost certainly a datasheet, with an RE suffix of unstated meaning. JEDEC 2N numbering identifies two-junction discrete semiconductors, usually transistors. Typical contents are pin diagrams, outline dimensions, maximum ratings, electrical characteristics and performance graphs. Technicians consult it to check a part in or out of circuit, confirm mounting orientation and choose an equivalent with suitable margins.
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.