ASUS archive for the X553MA model, compressed as RAR at about 1.15 MB. The name only adds an RG suffix whose meaning is not stated, so the exact contents, whether schematic, boardview or firmware, should be checked after extracting. Files for this laptop are commonly used to trace power circuits, locate components or restore firmware. Inspect what is inside before use, and compare the board revision printed on the motherboard with anything the documents state so you do not work from mismatched data.
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 @schematicslaptop. Enginerys does not host this file.
How to open a .rar file
Compressed archive — the usual wrapper for a schematic + boardview pair or a BIOS + EC set.