Xiaomi Mi 2S repair archive, 932 KB in RAR form. The file name names the phone model and nothing else, so the type of documentation inside is not stated and must be checked after extraction. Board-level material for a handset like this is used for tracing supply rails, identifying components near a fault, and finding test points for measuring voltages or resistance to ground. The Mi 2S is closely related to the Mi 2, yet details may differ, so confirm the PCB markings agree with the files.
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.