RAR archive of 1017 KB with the bare numeric name 1280, which might hint at a phone model number but states no brand or device type. The contents are unknown until unpacked, so inspect the files to see whether they are firmware, a flash file or documentation. Before writing anything to a device, confirm its exact model and hardware variant and keep a backup of the current firmware. Small archives like this often hold a single flash file, which must match the target precisely.
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 @Schematics_Mobile. 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.