Elta.7z.001 -

Large files are often split into smaller pieces (volumes) to make them easier to upload, download, or store on devices with limited capacity (like USB drives or email attachments).

This specific suffix indicates that this is Part 1 of a sequence. For the archive to be usable, you typically need all subsequent parts (e.g., .002 , .003 ) in the same folder. How to Extract .7z.001 files - Microsoft Q&A ELTA.7z.001

Based on the file extension and naming convention, is the first part of a split compressed archive created with the 7-Zip utility. Technical Definition File Type: A "split archive" or multi-volume file. Large files are often split into smaller pieces