ZIP archive for the IBM ThinkPad X31 ultraportable, 1.90 MB in size, with no board number or contents listed in the name. It most likely holds schematic or service documentation, so extract it and check what is inside before planning a repair. Material of this kind helps technicians trace power rails, review the power-on sequence and locate components on an older IBM planar. Compare any revision or FRU markings in the documents with those on your board, since IBM revised these systems during production.
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 .zip file
Compressed archive that every operating system opens without extra software.