Samsung SM-A127F repair archive in RAR format, about 2.29 MB, named only by the model code with no hint of its exact contents. Packs like this for Samsung phones usually carry service schematics or board layout pages, but open it to confirm before planning a repair. Typical use is tracing power rails from the PMIC, finding charging and display connector signals, and locating test points when chasing a short. Check that the model code on the device label matches, since regional variants can differ.
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.