ZIP archive of 193 KB tied to ET2220I, which matches the naming of an all-in-one desktop series, with V1.2 indicating version or revision 1.2. The name does not reveal whether it holds a schematic, boardview or firmware, so inspect the contents after extracting. For a board document, use it to trace power rails and locate components. For a firmware image, back up the original SPI chip first and check that the image size fits the flash. Match version 1.2 against the hardware before use.
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 .zip file
Compressed archive that every operating system opens without extra software.