PDF document of 96.6 KB for the 43CTQ080L, filed as a schematic but in practice a component datasheet. The 43CTQ family name matches dual common-cathode Schottky rectifiers in a TO-220 style package, and the L suffix usually denotes a variant in that series. Check the full marking on the part before substituting. A technician uses the sheet for the pinout, forward voltage, reverse rating and package outline when testing the diode in diode mode or choosing a replacement in a power supply secondary stage.
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.