You can display the contents of the header file by using the RESTORE statement with the CATALOG ONLY option and no FILE clauses.
A RESTORE with CATALOG ONLY produces the information in the same format as the backup log entry for an actual RESTORE.
You can get more information about the backup archive using the command-line utility db_backupheader, which accepts the file path corresponding to the first backup archive. The utility reads the backup archive file. It does not connect to the database.
The backup archive information includes:
backup information
database information at the time of the backup
dbspace information for each dbspace in the database
dbfile information for each dbfile in the dbspaces