Small 262 KB RAR archive for Apple board 820-2060, tagged LIO, which in Apple naming usually stands for the left input/output daughterboard carrying ports rather than the main logic board. The name gives no schematic number or revision, so the exact contents and version are unknown until it is unpacked. Such documents help trace port power, data lines and the connector that links the I/O board to the logic board. Confirm the 820 number printed on the small board before using it for diagnosis.
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 @Mac_Shematic_Santale. 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.