RAR archive labelled L640 U15, with no brand or further details in the name. The U15 token most likely refers to a board component designator, often the reference of a flash or EC chip, so the archive probably holds a dump of that chip, though this is not confirmed. Extract it and identify the contents before use. When programming, read the original chip first and check that the image size matches its capacity.
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 @vinafix_bios. 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.
7-ZipWinRARThe Unarchiver (macOS)