Small RAR archive of about 106 KB named landrex, with no brand, model or board number given. The name is uninformative, so the contents must be checked after extraction to see whether it is a tool, a firmware image or documentation. If it holds a BIOS or EC dump, read and keep a backup of the original chip before writing, and confirm the image size matches the flash capacity. If it is a diagram or boardview, match the board number to the PCB first, then use it to trace rails and locate components.
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 @cyberlanelectonik. 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.