ASUS C302C / C302CA Chromebook firmware for mainboard revision 2.0, in a 3.62 MB RAR. The name specifies a W25Q128 flash chip, which holds 128 Mbit (16 MB), so the image should be that size. Technicians program it to restore a Chromebook with corrupted firmware or a failed write-protect change. Check the chip marking for its voltage variant before connecting a programmer, confirm the board revision, and read the existing contents as a backup before writing anything.
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 @biosarchive. 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.
Back up your own chip before writing any dump, and match the full board number and revision. Flashing guide →