Venture into the land of naughty surprises with these stimulating kegel balls. Designed to be held within the vaginal walls and kept there by flexing the Kegel muscle, thus strengthening the vagina over time. Each ball is weighted by another interior ball that adds thrilling sensations as you move. Removal is easy with the addition of a convenient pull string. The balls are waterproof and completely phthalate-free for safe long-term use!