Part number 1N1199A is the only information in the name of this 104 KB PDF, which is indexed as a schematic but follows the JEDEC 1N pattern used for diodes, pointing to a component datasheet. The trailing A denotes a specific grade of the base type. Use the document to check electrical ratings, case style and which terminal is the cathode before soldering in a substitute. A standard PDF viewer is enough. Make sure the code on the original part matches, as unsuffixed and suffixed versions may differ.
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.