It is a rubber ring that goes around the base of the erm, wotsit thingy.

Attatched to the ring is a little pod about the size of a jelly bean, but a bit bigger.

The vibration occures inside the pod.

So when you are up to the hilt it vibrates upon the erm, ladies jelly bean.

If you position it right.

And yes I have, many times, it's great.

Call me Maninibat!