RAR archive for the Xiaomi Mi 4 smartphone, 1.32 MB in size. The name does not state what is inside, so it may be a schematic, a component placement or block diagram, or a mix of service documents. Phone repair technicians use such material to locate PMIC outputs, charging circuitry, display and camera connector pinouts and test points during board-level work. Extract the files and check the PCB version printed on the board before measuring anything, since phone mainboards often see small 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 @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.