The Duo Balls are a pair of soft rubber balls that have harder balls that freely move inside. They can be worn discreetly during the day and can bring orgasm after orgasm as they roll around, perfect for rediscovering the rocking chair or your morning walk. Duo balls are also great for improving pelvic floor muscles. Use the vaginal muscles to pull the the duo balls inwards as they are slowly removed using the pull string. It's kind of like a work out for your vagina. The new strength aquired from these exercises can help with incontinence, recovery from pregnancy, and improve your sex life! Duo Balls are closely related to Ben Wa balls, a very ancient and time tested pleasure and exercise device for women. Can also be used anally.