Small 38 KB PDF referencing the Microchip PIC18F8580, with the PIC18F8680 noted alongside it in the file name. At this size it is probably a brief product summary or errata rather than the full family datasheet, so expect limited detail. It can still help confirm device features, memory size and package before ordering a replacement or setting up a programmer. For pin-level work such as finding MCLR, PGC and PGD for in-circuit programming, cross-check against the complete Microchip datasheet for the exact part fitted.
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 @datasheet. 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.