Indicates this is the base game file, not an update or DLC.
Ziperto is a known repository for Switch NSP/XCI files. NINO-KNIRK-PE-NSwTcH-[BASE]-NSP-Ziperto.part1.rar
Use software like WinRAR or 7-Zip to extract the contents. You only need to extract part1 , and it will automatically pull from the other parts. Indicates this is the base game file, not an update or DLC