RAR archive of 2.43 MB coded 3CESV-RH-01, a related series to 3CESL, at what appears to be revision 01. The name carries no brand, device or file-type information. Extract and examine the contents before relying on it, and check embedded identifiers against your hardware labels. If it holds a flash image, read and keep the existing chip data with a programmer first. An image of the wrong size will not fit the chip.
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)