The file indicates that a larger dataset, software, or collection of files (possibly named "SS-Nin-030_s") was broken into smaller, numbered parts (e.g., .001, .002, etc.) to make downloading or transferring easier.
You must use 7-Zip or WinRAR to open the first file (.001) and extract the entire content. SS-Nin-030_s.7z.001
Based on the file naming convention, is the first part of a split 7-Zip compressed archive . The file indicates that a larger dataset, software,
To view or extract the contents, you need all parts of the archive (e.g., 001, 002, ...) in the same folder. To view or extract the contents, you need
To help you further, do you have the other parts of this archive (like .002 , .003 ) in the same folder? How to Extract .7z.001 files - Microsoft Q&A
The exact contents are unknown without extracting the file. It could contain anything, such as a dataset, game files, documents, or media.