PDF datasheet for the LM400RW1 LCD module, with no suffix, revision or panel size stated in the name beyond the part code itself. The LM prefix matches LG Display numbering for monitor-class panels. Documents of this kind specify interface signals, connector pinout, supply and backlight parameters, which are needed when tracing faults between a scaler board and the panel or when sourcing a replacement. Because the name omits the variant suffix, compare the full code printed on the panel before relying on details.
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 @cdispdata. Enginerys does not host this file.
How to open a .pdf file
The standard format for schematics, block diagrams, power-sequence charts and service manuals.