Rsync to a different ssh port

In order to use rsync with different ssh post, you can use -e flag, and supply ssh command with port option. For example, I want to transfer a file called /root/book.txt from a server called project.local with sshd running on port 55522 to local partition /mnt, I can use this command:

$ rsync -avz --progress -e "ssh -p 55522" root@project.local:/root/book.txt /mnt

where:
-a for archive mode
-v for verbose
-z to compress data during transfer
--progress for showing progress of the copy
-e to specify the remote shell to use, in this case to use ssh to port 55522