Basic command

rsync -av -e "ssh -p PORT" -P /path/to/local.file user@IP:/path/to/remote/folder

rsync -avzh -e "ssh -p PORT" -P user@IP:/path/to/remote/folder /path/to/local.file

# specify ssh key
rsync -avzh -e "ssh -i ~/.ssh/PRIV_FILE" -P user@IP:/path/to/remote/folder /path/to/local.file