This indicates a "split" archive. Large files are often broken into smaller pieces (e.g., .001 , .002 , .003 ) to bypass file size limits on certain storage systems (like FAT32) or to make uploading/downloading more manageable [1, 2].
A file named is the second segment of a multi-part compressed archive created using the 7-Zip utility . Technical Specifications
Do you have the of this archive, or would you like help identifying which program might have created it?