Zip of 1.68 MB with an aria2 1.34.0 build for LEDE on the x86-64 target, so it is a software package rather than a full firmware image. aria2 is a command-line download utility often installed on routers and small servers running LEDE or OpenWrt. The bundle probably holds an ipk package or binaries plus dependencies. Make sure the target system runs a matching x86-64 LEDE release before installing. Nothing in it is meant for writing to a flash chip, so keep it apart from device firmware dumps.
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 @tamirkaran_chanel. Enginerys does not host this file.
How to open a .zip file
Compressed archive that every operating system opens without extra software.
Back up your own chip before writing any dump, and match the full board number and revision. Flashing guide →