Hear them coming with these nipple clamps. These tweezer style nipple clamps hav e a bell attached at each end that makes a low pitched ringing sound. The tweeze r clamps have vinyl coated ends to provide a soft feel. The sliding ring allows for varying amounts of pressure to be applied. These are great clamps for begin ner or advanced nipple play. They are also great for humiliation play, and can a lso help locate subs quickly.