Named 89cnq135a, this 202 KB PDF is listed as a schematic but most likely is a datasheet for a dual Schottky rectifier module of the CNQ type, with 135 normally indicating the reverse voltage class and the a suffix a document revision or variant. The vendor is not stated. It helps confirm current rating, forward drop, pinout and package drawing when testing or substituting a rectifier in a power supply. Compare the full part marking with the sheet before ordering a replacement.
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.