Named 440cnq030, this 142 KB PDF is filed under schematics but gives no brand, device or revision. The code looks like a power rectifier module part number in the same family style as other CNQ-coded parts, though the contents should be checked to confirm. Sheets of this type document voltage and current ratings, forward characteristics, thermal resistance and mechanical dimensions. They are useful when testing a suspect rectifier in a high-current supply or selecting an equivalent part with matching ratings and footprint.
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.