Meizu MX5 archive in RAR format, 881 KB, whose name identifies only the phone model and not the file type inside. It is likely service documentation such as a schematic or placement diagram, but open it with WinRAR or 7-Zip to confirm. If diagrams are included, they assist in tracing supply rails from the battery connector, checking the charging and USB paths, and locating test points or components near a fault. Compare the PCB markings on your board with the documents, since phones can have several hardware revisions.
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.