When I saw this, I thought "Ohhh...I can either roll both curtains across or just one."  Little did I know that one of the bars would be used to hang my towels!  Super useful!  I just moved in and I literally keep my colorful curtain tied to one side and only use the clear one (I will roll across when guests come over).  Then I use the free bar to hang my towels.  Love this one.  Great quality.  I will buy again when I get a new place to live.