The extension .7z.004 indicates two primary things about the data:
You must have every part of the sequence (acwp.7z.001 through the final numbered part). acwp.7z.004
The suffix .004 means this is the fourth volume in a multi-part set. Why Files are Split The extension
The core format is 7-Zip (.7z), a high-compression open-source archive. a high-compression open-source archive.