You must have .7z.001 , .7z.002 , and any subsequent parts (like .003 ) in the same folder .
You cannot open or install this file by itself. You need all parts to reconstruct the game: SMTIVA-USA-(UNDUB)-CIA-Ziperto.7z.002
.cia (CTR Importable Archive), used for installing games on a hacked 3DS via FBI . You must have
Open only the first file ( .7z.001 ) using a program like 7-Zip or WinRAR. You must have .7z.001
Extract the contents. The software will automatically pull data from part .002 to give you a single .cia file.