Revision 3 of a datasheet for the 1N5817, the 20 V part of the 1 A Schottky rectifier family, supplied as a 96.3 KB PDF and filed as a schematic. The dx tag likely relates to the publisher document code, though the name does not identify the company. Contents typically include ratings tables, characteristic graphs and the axial outline. Use it when replacing low-drop rectifiers in input protection or converter stages, and check that the original part number matches before substituting.
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.