PDF reference sheet for the 2N3391A, 296 KB, catalogued under schematics; the A suffix is part of the part number as given in the name. Its size matches the other 2N339x entries, suggesting a combined family datasheet. The document supplies electrical characteristics, limits and package drawing for this 2N-series transistor, which helps when choosing a replacement or checking lead order. Opens in any PDF reader. Make sure to read the 2N3391A figures, not those of the plain or neighbouring numbers.
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.