BetterZip has unrar capabilities included that let you open and extract rar archives. To create and save RAR archives, BetterZip can download and install the rar commandline tool from the win.rar GmbH web site or you can tell BetterZip the location where you have it already installed. Please note that BetterZip does not include a rar license. You will have to purchase it separately from win.rar GmbH.
Go to Prefences > Helpers and click the Button Download & Install Rar. Once BetterZip knows the correct path to the rar tool, you can save and create RAR archives as if BetterZip had it built in. RAR archives can be password encrypted and split into multiple volumes.
With the rar tool installed, BetterZip can also recreate lost volumes, if recovery volumes are available and repair damaged archives, if the archive was built with enough recovery records. BetterZip will offer to repair archives automatically, when you try to open and extract them or when errors are found during testing.
To create recovery records or volumes use the field “additional parameters” in the preset configuration or the save panel. Read all about the rr and rv switches in the rar doumentation included in the rar download package.