: The file format used for installing games on a Nintendo 3DS.

: You must have every part (e.g., part1.rar and part2.rar ) in the same folder on your computer.

Because this is "Part 2," you cannot open or install it on its own. Multi-part RAR files are used when a single game file is too large for one download link.

: Use a tool like WinRAR or 7-Zip. Right-click on Part 1 and select "Extract Here". This automatically pulls data from all the other parts to recreate the single .cia game file.