Archive for the Lenovo IdeaPad U350 ultraportable, 1.54 MB in RAR format. The name says nothing about its contents, ODM or board number, so open it to see whether it holds a schematic, a boardview or firmware. Service material of this kind is normally used to trace power rails, find test points and work out which component causes a short or a no-boot condition. Whatever is inside, check that the board identification in the files matches the number printed on the U350 motherboard before relying on it.
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 @alischematics. 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.