Yeah, but the ones in this picture are actually Baoding balls, which are used to exercise the hands. Ben Wa balls are usually, though not always, connected by a string or chain for easier removal.

I have to say this because my stepfather, who is Chinese, gave me a pair of Baoding balls that look almost exactly like the ones in the photo, right down to the fabric on the box. Being that I was ten years old and he is a good and decent human being, I’m pretty sure he didn’t intend me to insert them into any bodily orifices.