Covering the range 1N821 to 1N829, this 41.9 KB PDF is a series datasheet for a family of JEDEC 1N diodes, despite being indexed as a schematic. The name gives no manufacturer or revision. Series sheets let you look up each member side by side, which helps when the original part is partly legible or when choosing a substitute with equal or better ratings. Open it in any PDF viewer and check the exact type number on the component before taking values from the table.
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.