PDF datasheet for the 1N5403, rated 300 V in the 1N5400 series of 3 A general-purpose rectifiers, filed as a schematic though it documents one component. The 43.4 KB file gives no manufacturer or revision. Expect reverse voltage and forward current ratings, surge limits and outline dimensions. When a rectifier tests shorted with a meter, this sheet helps pick a correct part. Any higher grade from the same family generally works, but check the original marking and the cathode band before soldering.
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.