Archive in ZIP format, 769 KB, titled N68-S, most likely referring to a motherboard of that model name. The name gives no revision, vendor or file type, so extract it and inspect what is inside before use. Small archives like this usually carry a BIOS image, a flashing utility or a datasheet. For a firmware image, back up the current SPI chip first, check the dump size against the chip, and match the model and revision printed on the board.
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 @laptopchiplevelrepair. Enginerys does not host this file.
How to open a .zip file
Compressed archive that every operating system opens without extra software.
Built-in OS tools7-Zip