: An encrypted TrueCrypt container (historically used for "on-the-fly" disk encryption) that has been compressed and divided into smaller pieces for easier storage or transfer.
: To open it, you must have all numbered parts in the same folder. Opening the first part (.001) in 7-Zip will automatically detect and join the subsequent parts, including .004. Context: TrueCrypt and 7-Zip TC.7z.004
Historically, users combined these two tools for maximum security and storage efficiency: Converting TrueCrypt Volumes & Partitions - VeraCrypt : An encrypted TrueCrypt container (historically used for
: A split volume of a compressed archive created with 7-Zip . TC.7z.004