Cousins4.7z.001 «Edge Premium»
If you can provide more context on where you found this file, I can give a much more accurate write-up. This file name is typical in several scenarios:
Run a command to merge them back into a single archive (if your extraction tool doesn't do it automatically): Cousins4.7z.001
Used in training simulations to teach investigators how to carve files out of raw disk images or network captures. If you can provide more context on where