Firmware for the Mercusys AC12G wireless router, hardware version V1, packed in a 1.54 MB RAR with a 2MB flash size noted in the name. A full dump like this is used to unbrick a router that no longer boots, by writing the SPI flash with an external programmer or through a recovery method. Check the hardware version on the router label, since images for other versions differ. Read the original chip before writing to keep calibration data, and confirm that the flash chip is really 2MB.
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 →