Nowadays, most jiggle balls sets come with strings or sets of strings rather than being sold as single balls. The purpose is to make inserting and removing the love balls easier and safer. Leaving the string dangling downward, you can insert the jiggle balls into your vagina while the string passes through your vagina lippy. If you want to take out the ball, you can gently pull on the string and it will slide right out, no digging required!