RAR archive of 10.1 MB named A500H SM, where SM most likely stands for service manual, though the brand and device are not stated in the name. Service manuals typically cover disassembly steps, part lists and sometimes schematics or troubleshooting flowcharts. Extract it and check the documents inside to identify the exact model they refer to. Confirm the model and board revision on the unit match the manual before following procedures or ordering replacement parts based on it.
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 @one5technology. 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.