These smart balls make it possible to train your pelvic floor muscles in a playful and fun way. During everyday activities, the Smartballs Duo trains the sensitivity of the inner muscles, strengthening the pelvic floor muscle. Smartballs Duo includes two balls that are perfect for all those who have already trained successfully with the Smartball Uno. Muscles that are back in shape promise more sensation during sex. An ergonomically shaped finger hollow makes insertion easy and a woman can go about her day without interruption while at the same time be training diligently. The new Smartballs design includes a conically tapered ball to ease insertion and an almost completely silent steady and intense rolling motion of the inner balls. Smartballs are hypoallergenic, gentle to the body and include a flexible silicone retrieval band. Always use a water-based lube with Smartballs.