This is the custom name given to the file by the person who created it.
Most email providers won't let you send a 5GB file, so you might split it into several 25MB parts. KR5.7z.001
Do you have the of this file saved in the same folder? This is the custom name given to the
If you try to extract .001 but .002 is missing, the process will fail with an error message saying the archive is corrupt or the "volume is missing." KR5.7z.001