Archive for the ASUS X451MA motherboard, revision 2.1, stored as a 104 KB ZIP. Its contents are not stated, but the small size suggests a boardview file. A boardview program such as OpenBoardView or FlexBV lets you search for a reference designator or net and see its position and connections on the PCB. Confirm that your board is marked X451MA rev 2.1 before relying on it. It is useful for tracing power rails, locating components and test points, and narrowing down a short 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 @ITHINKHS. Enginerys does not host this file.
How to open a .zip file
Compressed archive that every operating system opens without extra software.