Factory image package named emerald, marked ENG ROM, which points to an engineering build rather than a retail release. The name gives no brand or model, so the target device has to be confirmed before use. The archive is a 1.58 GB ZIP, a size typical of a full Android factory image with system, boot and recovery partitions. Factory images are normally flashed with fastboot or the vendor tool after unlocking. Back up user data and confirm the device codename matches, since a wrong image can leave the unit unbootable.
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 @mrepairo. 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 →