If you like to lie back and enjoy the ride, the hands-free strap-on model is for you.  Strap the elastic belt around your pelvis, position the stimulator on your clitoris and vary the vibrations with the hand-held controller.  Many models are just for clitoral stimulation and can look like butterflies or bumblebees, while others came with vibrating penetrators for clitoral as well as vaginal and g-spot stimulation. There are also "strapless" strap-ons, such as the Feeldoe." They fit in snugly and stay in place.