Apple iPhone 8 archive of 53.1 MB, a size suggesting schematics, boardview data and possibly additional reference images. No board number or revision appears in the name. Use it to diagnose power faults, missing rails, charging issues or shorts by locating parts and test points on the logic board. Boardview files require a suitable viewer, while schematics open as PDF. Verify the logic board variant, since iPhone 8 boards differ by modem type.
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 @schematicslaptop. 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.
7-ZipWinRARThe Unarchiver (macOS)