The clover clamp, also referred to as “butterfly clamp” or “bird clamp” is of Japanese origin and was designed for clamping sails or sewing fabric. The clamp is flat, about 4 inches long and 2 inches wide, and has an eyelet where the power cord is attached. This provides the electro-shocking sensation. When the cord is pulled a mechanism inside the clamp moves the jaws closer together and provides increasing tension. Add the electro-shocking sensation to create a very high level of pain. When the clamps are removed the restricted blood flow rushes back into the nipples and releases oxytocin, a hormone associated with orgasm.
Nipple clamps are used to cause pain in the nipples as part of certain BDSM activities. They are also used to produce erotic stimulation as part of nipple play. In this context they are not primarily used to produce pain but rather to increase nipple sensation. Their use traps blood in the nipples, increasing the sensitivity of the nipple.
Before the clamps are applied the nipples are typically stimulated manually or orally to prepare them. Once the nipples are erect they are held taut and the “jaws” of the clamps are closed slowly, usually on the base of the nipples where they meet the areolae. Subsequently the tension is increased, and this is often accompanied by additional manual or oral stimulation.
For safety reasons the length of time for which nipple clamps are worn is limited. Bruising and soreness can result if they are used for more than 10 minutes at a time. If the blood circulation to the nipple is cut for too long there is also a risk of damage to the tissue and nerves. Changes in skin colour can be used to determine the level of blood flow, which needs to be re-established regularly to prevent any permanent damage. When the clamps are removed the restricted blood flow rushes back into the nipples and releases oxytocin, a hormone associated with orgasm. This can make skin sensations more intense and pleasurable. The restriction and reintroduction of blood flow into the nipples can be painful, and this is used as part of some BDSM activities such as breast torture.