RAR archive labelled Meizu M6, roughly 3 MB; the file name names only the phone model and says nothing about what kind of documents are inside. In phone repair collections these packs usually contain schematics or component placement maps used to trace power rails, locate test points and identify parts near the charging IC or PMIC. Unpack the archive to check formats and contents, and verify that any board code shown matches the PCB in your device before relying on the data.
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.