Small RAR archive, 1.29 MB, labelled for the OPPO R7s smartphone. The file name carries no further detail about board revision or document type, so the contents must be checked after extraction with a tool such as WinRAR or 7-Zip. At this size it is more likely a schematic or layout PDF set than a firmware package. Diagrams of this kind let a repairer follow power lines, locate connectors and identify components near a fault, provided the PCB version on the phone matches the one in the documents.
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 @SMART_PHONE_SCHEMATICS. 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.