SMARTBALLS DUO is the easy-to-use training partner for those who have already trained with the SMARTBALL UNO or who already naturally have a stable pelvic floor. Especially suited for experienced users. Inserted like a tampon, the SMARTBALLS DUO adapts to the body and can barely be felt when worn. The constant and nearly soundless rotation of the inner balls works with everyday movements to set off muscles contractions thereby strengthening the pelvic floor. Short, regular training phases lead to the most effective improvements. As with any muscle group, the fitness gained goes away if training is discontinued so even after a successful stabilization of the pelvic floor, SMARTBALLS should be continuously used for maximum results.