Specifically designed to be held within the vaginal walls and kept there by flexing the Kegel muscles, the tightness of your vagina is guaranteed to increase over time enhancing pleasure for both you and your partner in the long-run! And, as each ball is weighted, thrilling sensations will be experienced with every move you make. Easy to remove due to the convenient pull-string, these balls are completely waterproof, safe for long-term use, and measure-in at 9.5`` in total length.