RAR archive of 1.40 MB for an Apple MacBook Air built on logic board 820-00165-A, labelled with the J113 project code. Apple numbers its logic boards 820-xxxxx with a revision letter suffix. Content is not listed, but a package of this size usually contains the schematic or boardview, used to trace power rails, find test points and track down shorts on the board. Confirm the 820-00165 number silkscreened on your logic board before working from the drawings or any included firmware.
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 @SCHEMATICWORLD. 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.