RAR archive for the Toshiba Satellite U920t, naming board FLXOMB1 and the code A3353A, which is probably a board part or assembly number. The contents are not listed, so it may hold a BIOS dump, a boardview or schematic material; extract it and check. If it is firmware, read the original SPI chip with a programmer before writing and confirm the image matches the flash capacity. Also match the board code on the PCB before use.
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)