You can "look into" the archive without fully extracting it by using a compatible archive manager: Can you recommend me a best RAR extractor for Mac?

: To see what is inside, you usually cannot open Part 3 by itself. You must have all preceding parts (Part 1 and Part 2) in the same folder.

Files named with "Part 3," "Part 003," or ".r03" are segments of a larger file that was split into pieces for easier transmission or storage.