A 113 KB PDF for part 10WQ045FN, catalogued as a schematic but almost certainly a manufacturer datasheet. The name matches International Rectifier numbering, where the FN suffix normally marks a particular package option. Inside you should find maximum ratings, electrical characteristics and a footprint or outline drawing. Technicians use it to confirm package compatibility and ratings before replacing a surface part, and should compare the device marking with the datasheet ordering information.
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.